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7.62x40mm Information Thread (Page 5 of 35)
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I don't have any experience with the del-ton barrels, I have heard they use Wilson.... I have rechambered a few of the Model 1 barrels.....of the last 4 I did, 1 shot good (MOA accuracy) the other 3 shot between 3&4MOA....2 of the 3 that shot big groups were slug checked and found the bores to be pretty tight and could use a good bit of tool mark clean-up....the Model 1s that we did are used as 'blasters' not benchguns so I guess it depends on what level of accuracy you are looking for....I am in the process of lapping one of the Model 1s to free up the bore a little and smooth out the tool marks to see if it helps the accuracy.... I'm not a big proponent of using the 1:8 twist in a supersonic 110 to 125gr set-up, but until a slower twist similar expense alternative comes along the Model 1s are working well as inexpensive 'blasters'.... with the variance in bore size we have found, and the potential for pressure and accuracy problems associated, the only interest I have in rechambering one, as with the others that I have done, is to do it as a complete upper so that it can be bore checked, lapped as needed, then test fired. (standard disclaimer: this is a wildcat non-standardized cartridge use at own risk) You can buy the parts you want to use and send them to me and I'll help you get one running, probably take a week, we can work something out on the cost depending on the components you choose to use and what the Model 1 bore looks like and how much lapping it may require if you elect to go with that barrel.....reloading dies probably won't be available for a few more weeks... Hope this helps, Kurt |
" The only way I got to keep them Tigers busy is to let them shoot holes in me..."
I ended up hand lapping my Model 1 barrel using the borebrush / patch method doing 400 strokes with 800 grit lapping compound...then fire lapped with 8 shots of long bearing surface sub-sonic 220s coated with polishing compound......groups went from 3 and 4 inch to a little over 1"......velocity came up and pressure signs on some of the hotter loads went away IMR 4227 Range Data: (standard disclaimer as with any wild-cat, use at own risk and work up slow) Test Rifle 16" 1:8 Model 1 300-221 rechambered in 7.62x40mm .125 gas port carbine length gas system, fire-formed brass... 125 TNT 21.0gr IMR4227 = 2,257 fps 125 TNT 22.0gr IMR4227 = 2,330 fps 135 SMK 21.0gr IMR4227 = 2,240 fps 135 SMK 22.0gr IMR4227 = 2,325 fps Test Rifle 20" 1:12 Noveske 7.62x40mm rifle length gas system, fire-formed brass... 125 TNT 21.0gr IMR4227 = 2,315 fps 125 TNT 22.0gr IMR4227 = 2,470 fps 135 SMK 22.0gr IMR4227 = 2,405 fps 40 |
" The only way I got to keep them Tigers busy is to let them shoot holes in me..."
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[div class='quoteStyle']Originally Posted By bfarrin1:
[div class='quoteStyle']Originally Posted By 762x40mm: Test Rifle 20" 1:12 Noveske 7.62x40mm rifle length gas system, fire-formed brass... 135 SMK 22.0gr IMR4227 = 2,405 fps 40 There is a lot to like about that. I'm hoping that when the mid-length 20" barrels come in it will open the 20" barrel up to a little broader powder selection, but the 1680 and 4227 (both) seem to be pretty close....I just saw your post but I sent a e-mail earlier on my other wildcat build....I know it's not a AR but I hate to miss the chance to be a picture whore.... 
 
So far pretty happy with 1/4MOA......going to Fort Polk in a week or so to shoot some 600 yard stuff.... 40 |
" The only way I got to keep them Tigers busy is to let them shoot holes in me..."
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[div class='quoteStyle']Originally Posted By Kag:
Anything new??  
We've been a little preoccupied for the last few days 
Gustav kinda slowed down our gun stuff in southwest LA 
I'm hoping to be able to make a few phone calls later in the week once things get a little more back to "normal" Having to do this with a cell phone tethered to a lap-top..... thanks, Kurt |
" The only way I got to keep them Tigers busy is to let them shoot holes in me..."
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762x40 Oops forgot your down south. Hope all is well on your end. Didn't want to nag, just hadn't seen anything posted here in a while. I'm hoping I can get a 40 build done by late oct or early nov so I can go blast a critter and post the gory details. I'm thinking the 40 should do nicely for deer. Kag |
we lucked out, skirted us to our northeast, very minimal wind damage, double duty on the yard work though..... I am also looking forward to this hunting season....hope to have eight or ten 40s in the field.....most of the guys I have spoken to are going to use the Nosler BT or Sierra Pro Hunter 125s.....any thoughts on what you are going to try?.... I hope to have a status update by tomorrow or Thursday..... Thanks, Kurt |
" The only way I got to keep them Tigers busy is to let them shoot holes in me..."
the 63 is one we've been working on for a while.....following the improved 30-06 concept similar to the 300 Hawk, the 63 has a different shoulder angle and little more capacity...have been pretty happy with it so far.......got to shoot it a little before Gustav, had three groups at 200yds in the .200" range, most were around .500" to .600"....I can't say enough good about the PacNor SuperMatch barrel on this thing, very happy..... Thanks for the enthusiasm, Kurt |
" The only way I got to keep them Tigers busy is to let them shoot holes in me..."
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Kurt, glad you guys stayed dry, taking down PNPP is always a bear ... that's the good thing about our spot, we're inland far enough. I was looking in the Hornady manual and comparing the x40 numbers and this puppy just smokes! Kurt's x 40 16" barrel AR, 125 gr bullet, 2250-2330 fps 16" barrel AR, 135 gr bullet, 2240-2320 fps 7 BR in Hornady's Manual 15" barrel TC, 120 gr bullet, 2200-2300 fps 15" barrel TC, 139 gr bullet, 2100-2300 fps Solid 7BR performance out of an AR, now what's not to like about that! |
“The patriot volunteer, fighting for country and his rights, makes the most reliable soldier on earth”
luckily for us, taking it down is usually a process/operations headache .....we just have to fix it after the wind twists it up
Awww man....gee thanks Marty, now the benchrest guys are gonna want to kick my ass too All in fun, thanks for the 7BR info/comparison..... Kurt |
" The only way I got to keep them Tigers busy is to let them shoot holes in me..."
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Just to let everyone know that has inquired....I talked to Noveske today and was told that the barrels have been contoured and are in process to be chambered..... No word yet on the dies, hope to know something tomorrow..... Thanks, Kurt |
" The only way I got to keep them Tigers busy is to let them shoot holes in me..."
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[div class='quoteStyle']Originally Posted By SquirrelXss:
Im very intrested in this caliber, seems like a natral to me, being as i will be building a .300 whisper soon. Ill keep on reading till i get that one done. Thanks for the interest......have a little more info for everyone from last week.... I had ordered a couple contoured blanks a while back to conduct a little more barrel testing....they came in mid part of the week and I got to chamber and test one this weekend...I had hoped that the bore would be somewhere between .308 and .3085 to test the other end of the spectrum from some of the .3065 ~ .307 barrels I had chambered recently....well my wish got answered, kinda.....the bores checked ~ .3095.....I went ahead and chambered one and put about 200 rounds through it this weekend....surprisingly with the .309 bore, as long as I did my part it maintained around 1.5" groups with some bulk loads of 125gr TNT and 21.5gr of IMR4227 @ ~ 2,350fps..... 
The barrel is a 6 land/groove 16.5" 1:12 twist......ended up shooting very good and did not exhibit the pressure signs found with some of the tighter bore .307 barrels that we chambered recently.... also tried out a couple muzzle attachments.... the OPS INC R3E2C 
and the Noveske KX3 
the R3E2C made a noticeable difference in recoil with the loads we shot today (didn't fall near as much off sight picture and allowed for faster follow up shots on the 200yd plates).....but equally noticeable in additional percussion and report, especially to adjacent shooters.... The KX3 made the rifle more pleasant to the shooter, kept the percussion and report out in front.....it is slated to be installed on a SBR project that we are working on...... Hope this helps, Kurt |
" The only way I got to keep them Tigers busy is to let them shoot holes in me..."
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7.62x40mm Range report. Well 762x40mm sent me the upper in the post above (and shown below) with about forty pieces of brass. Since the dies for this cartridge are currently being manufactured, brass is made using 300-221 fireball dies. So using the brass that 762x40mm sent as a guide, I set up my redding 300-221 fireball dies to make some more brass from once fired 223 brass. The first forty pieces of brass that I made, I set the die to expanded the 223 case in one pass. Out of the forty pieces I spit about three. The second set of forty pieces I set the Redding dies to do it in two passes, first to 7mm the second pass to 7.62mm. I did not split any brass with the two step method. I then trimmed my eighty pieces to length. Making brass for the 762x40m is easier than making 300-221 fireball brass.  I decided to see just what velocities I could get from Winchester 147 grain full-metal-jacket-boat-tail bullets. I choose to start with these because they are an inexpensive bullets (about $168/1000) that I can practice with and shoot pretty similar to the 135 and 150-155 grain bullets that I use in competitions. I reload some samples using the following powders Reloader-7, IMR-4227, W296, and Lil-Gun. I only managed to get through the W2996 loads because on lighting and battery issues with the chronograph in the in-door range. So here they are: ***standard disclaimer as with any wild-cat, use at own risk and work up slow*** 147 g Win. FMJBT sectional density = 0.221 Ballistic Coefficient = 0.391 C.O.L. = 2.26" 147 g Win. FMJBT 18.0g W296 = 2098 ± 17 fps 147 g Win. FMJBT 19.0g W296 = 2177 ± 18 fps (Makes USPSA major rifle power factor) 147 g Win. FMJBT 20.0g W296 = 2241 ± 11 fps **MAX LOAD IN TEST RIFLE** 147 g Win. FMJBT 21.0g W296 = 2312 ± 9 fps **CAUTION HIGH PRESSURE LOAD DO NOT USE** ** 2 of the 5 cased has loose primer that could be pushed out by hand! 762x40mm, thanks for developing this cartridge. It can use standard unmodified mags (I used unmodified 30-round Pmags for the test), standard unmodified bolt and carrier, and make major power factor...  320pf
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320pf, thanks for the load data!!!....great to see field feedback coming in.....looks like you are getting some great numbers ....I also recently purchased some of the 145FMJ M80s (free shipping) from Wideners....they ended up being around 12 cents each and the free shipping is a pretty good deal considering a box of bullets is around 45 pounds.....once up and running, the 145s will probably end up being the go-to bullet in my SBR....I have a question about how you were forming your brass.....were you expanding the .224 neck out to 7.62 and then cutting to length?... or were you cutting the neck off and then expanding the shoulder down to 7.62?....I've had a 0% brass loss to split cases by cutting the neck off down to the shoulder, deburr the inside and outside, and one pass down to 7.62.....I agree, the 40 brass is much easier to make than 300 whisper brass, not near as much cutting.... congrats on making Major PF with a 16"  thanks again, Kurt |
" The only way I got to keep them Tigers busy is to let them shoot holes in me..."
I have a couple of the Model 1 .30 cal barrels that I used as test barrels.....I'll probably be putting them up on the equipment exchange....one has a short throat set up for a pinned gas block and the other has a longer throat set up for a clamp-on or set screw gas block..... I think the 1:8 twist is a little on the fast side for the super sonic 125s and 135s....even the 150s at 2,000 to 2,100 fps should only need around a 1:11 ~ 1:12 twist...... the 1:8 barrels that we tested produced decent groups, no stabilization issues....we as others have found with this and other cartridges that excessive twist, tight bores, and the type of rifling or number of grooves and lands has an impact on the performance of the cartridge and can display a mechanical disadvantage compared to an ideal barrel for a given cartridge.....they will work, just less than ideal..... hope this helps, kurt |
" The only way I got to keep them Tigers busy is to let them shoot holes in me..."
Kurt, I miss-placed the .22 pilot for my trimmer so for the first set of brass that I made I sized and expanded the necks first and then trimmed them. I found my .22 pilot so tonight I made another thirty pieces. I trimmed them first and then sized and expanded the necks. I did not split any cases this time around. So your method of trimming the case before sizing and expanding the neck is the way to go 320pf |
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320pf,
thanks for the continued feedback and update on the brass forming, hope everything is going well.... I spoke to Noveske and the 7.62x40mm barrels shipped Friday, they should be here the end of next week
for those that have inquired about our other AR-15 wild-cats, please find a couple pics of our latest.....the .25x40mm (AKA: CottonMouth, named for all of the snakes we pulled out of a friends Sabine Pass home after Ike).....designed around the .223 parent brass and the 100gr Matchking and Gameking....should have some range feedback shortly, working on a couple other projects.... the .25x40mm in a un-modified PMAG, 100gr SMK  
Left to Right: 300Whisper, 7.62x40mm, .25x40mm, 5.56x45mm 
thanks all for the calls of concern after Ike, Kurt |
" The only way I got to keep them Tigers busy is to let them shoot holes in me..."
Still waiting on die delivery date, hopefully soon ........with a 100gr Matchking we're hoping to get around 2,600fps with the .25x40mm out of a 16" barrel....should know more on the .25 by next weekend.....when the 7.62x40 barrels arrive I'll let everyone know..... Thanks, Kurt |
I cant wait to see how they turned out. Any word on the progress with the dies? That 25x40 looks interesting. Any ideas on projected/targeted velocity ranges. Looks fun
" The only way I got to keep them Tigers busy is to let them shoot holes in me..."
Thanks for the interest......no difference in priority, I attack all with equal vigor ....the .25x40mm came about from a conversation with a friend for a low recoiling round for his 11 year old daughter to hunt with...something bigger than .22 centerfire...Let me gain a little more momentum with it and I'll post what I have..... Thanks again, Kurt |
" The only way I got to keep them Tigers busy is to let them shoot holes in me..."
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Fort Polk Range 23 Alpha
Took the original prototype 7.62x40mm 20" Noveske out today to stretch its legs a little to see what the old gal could do.... 
Range 23 Alpha is a 475 yard recreational range located at Fort Polk in Louisiana.... Loaded up a mag of 135 Matchkings with 22.5 grains of Hogdon 4227 at 2,410 fps....the 135 Matchkings delivered close to 700 ft/lbs of energy at 475 yds... this is what the 11"x17" targets look like at 475 yds from the bench.. 
targets at 10X camera magnification...put 'em up on the berm to try and get away from the heat monkey.... 
now through the glass at 10X magnification.... 
fired three sighters at 100 yards to check zero and range table.....took appx. 16" of elevation to hit at 475 yds.... considering the cross wind at 300 yds, (really evident in group#1) am very happy with the 135s....the more the wind and I calmed down the better the groups got....with range shut-downs it took almost three hours to shoot the three groups  ......
Hope this helps, Kurt |
" The only way I got to keep them Tigers busy is to let them shoot holes in me..."
I've been looking for just the right cartridge for my girls. No recoil, low muzzle blast, but with midrange velocity for training out to 400 yards. I can't wait to hear any results you have. David |
yes, it is on the base.....it is open to the public....you have to jump through the normal hoops....drivers license, proof of vehicle insurance, vehicle registration = visitors pass there is a 600 yard range here in Lake Charles but access to it is not all day....part of the range is used for skeet and sporting clays so the rifle side gets shut down.... when I lived in Baton Rouge we used to go up by the State Police center on the Mississippi River and over to Kentwood....bumber having to drive that far.... |
" The only way I got to keep them Tigers busy is to let them shoot holes in me..."
Hi David, the numbers that we are hoping to get out of the .25 should better most .223 loads out to 400 yds.....the BC on the 100 Matchkings is decent so that should help... The numbers that we are looking for from a 16" barrel: .25x40mm load of a 100gr Matchking at 2,500 fps 1,380 ftlbs of energy at the muzzle 1,150 at 100 yards 950 at 200 yards 781 at 300 yards with a 7.1” high flight path Hope this helps, Kurt |
" The only way I got to keep them Tigers busy is to let them shoot holes in me..."
I think there is a 6x35or37 out there called the 6CQB if I remember right.....if you decide to do a 6x40mm I can send you the numbers on the one we worked up if interested....the 6x40 should be pretty slick with the 107 SMKs .520 BC Kurt |
" The only way I got to keep them Tigers busy is to let them shoot holes in me..."
I'm hoping the Noveske barrels should be available by next week....I don't have a delivery date yet on the dies, should be getting close.....
I had a small number of test barrels made that I will probably end up selling at some point, other than those the Noveskes are it.... thanks, Kurt |
" The only way I got to keep them Tigers busy is to let them shoot holes in me..."
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Kurt Thanks. I've decided to put my 6.8 project on hold pending those barrels. This is a very interesting cartridge...and I already reload for .308, so that takes care of the projectiles! I don't mean to be asking questions that have been answered before, but this is a long thread... is there factory ammo support? Andrew |
I've met Gov. Sarah Palin and was very impressed.
Hi Andrew, thanks for the interest and questions.....the 40 is a wild-cat, no factory ammo support....have to roll your own ......I need to get with a couple of the shops that load for the Whisper to see if they would be interested in taking on the 40.....I have been talking with a fella about turning out formed brass, should make life easier.....thanks, Kurt |
" The only way I got to keep them Tigers busy is to let them shoot holes in me..."
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Range Report: I had a chance to finish the reloading tests that I started with Winchester 147 grain full-metal-jacket-boat-tail bullets. As I mentioned in an earlier post, I choose use these because they are an inexpensive bullets (about $168/1000) that I can practice with and shoot pretty similar to the 135 and 150-155 grain bullets that I use in competitions. I reload some samples using the following powders Reloader-7, IMR-4227, and Lil-Gun. Here they are: ***standard disclaimer as with any wild-cat, use at own risk and work up slow*** 147 g Win. FMJBT sectional density = 0.221 Ballistic Coefficient = 0.391 C.O.L. = 2.26" ------------- Lil'Gun ---------------- 147 g Win. FMJBT 18.0g Lil'Gun = 2178* ± 20 fps; K.E.= 1548 ft-lbs (Makes USPSA major rifle power factor) 147 g Win. FMJBT 19.0g Lil'Gun = 2124* ± 87 fps; K.E.= 1472 ft-lbs 147 g Win. FMJBT 19.0g Lil'Gun = 2132* ± 19 fps; K.E.= 1483 ft-lbs 147 g Win. FMJBT 20.0g Lil'Gun = 2370* ± 20 fps; K.E.= 1833 ft-lbs (Makes USPSA major rifle power factor) 147 g Win. FMJBT 21.0g Lil'Gun = 2282* ± 12 fps; K.E.= 1699 ft-lbs (Makes USPSA major rifle power factor) ------------- IMR4227---------------- 147 g Win. FMJBT 18.0g IMR4227 = 2170 ± 10 fps; K.E.= 1537 ft-lbs 147 g Win. FMJBT 19.0g IMR4227 = 2079* ± 42 fps; K.E.= 1472 ft-lbs (one low vel. flier) 147 g Win. FMJBT 19.0g IMR4227 = 2141* ± 9 fps; K.E.= 1496 ft-lbs 147 g Win. FMJBT 20.0g IMR4227 = 2153 ± 18 fps; K.E.= 1513 ft-lbs ------------- ReLoader-7 ----------------- 147 g Win. FMJBT 19.0g ReLoader-7 = 1818 ± 20 fps; K.E.= 1079 ft-lbs 147 g Win. FMJBT 20.0g ReLoader-7 = 1932 ± 20 fps; K.E.= 1218 ft-lbs *reloads were done using unfireformed brass It seems that using un-fireformed brass results in increases shot to shot deviations. As mentioned in my earlier post, this cartridge use standard unmodified AR15 mags and standard unmodified bolt/carrier. The 20 g and 21 g Lil'Gun loads pushing the 147 g Win. FMJBT at ~2300 to 2400 fps produces a muzzle energy of 1700 to 1800 ft-lbs. Kurt, (a.k.a 762x40mm, thanks again for this cartridge. 320pf
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320pf, thanks for the contiued field feedback.....the lil-gun is smokin ......please keep us up to date on your other loads and tests....thanks again, Kurt |
" The only way I got to keep them Tigers busy is to let them shoot holes in me..."
salt and pepper......maybe Tobasco sauce....... |
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Originally Posted By uptown1:
Originally Posted By JFA:
A good while back bfarrin queried me about anyone that made a .038 match barrel for 7.62x39. I have some .308 -11 twist 5 groove match barrels 1" diameter. Pm me if anyone is interested. salt and pepper......maybe Tobasco sauce....... It took a minute but I finally got it........please play nice...... anyway........the big brown truck just left...... Noveske 40 variants: 20" crowned barrel, rifle length gas system 20" crowned barrel, mid length gas system 20" threaded barrel, mid length gas system (5/8x24) 16" threaded barrel, mid length gas system (5/8x24) 16" threaded barrel, carbine length gas system (5/8x24) 16" crowned barrel, carbine length gas system 
each barrel is marked 7.62x40 12P (1:12 polygonal) 
each barrel is individually serial numbered (last few numbers covered) 
and the Noveske cross 
as of a few nights ago the 20" barrels have been spoken for.....there may be a 20" crowned muzzle available, have not heard from the requestor in a while.... the next most popular have been the 16" carbine gas system threaded muzzle....only a couple left.... the word on the dies is they are in the shop in process....no definite delivery date.... To all at Noveske....barrels look great, very high quality and nice finishing touches.....thanks and great job... Hope this helps, Kurt |
" The only way I got to keep them Tigers busy is to let them shoot holes in me..."
I don't want to offend the moderators by putting prices and stuff in the technical section unless it is ok with them.....I've heard $$$$ in the technical section is a no no....PM me and I can tell you what is still available and $$$$..... thanks, Kurt |
" The only way I got to keep them Tigers busy is to let them shoot holes in me..."
7.62x40mm Information Thread (Page 5 of 35)
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