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[ARCHIVED THREAD] - 6.8mm SPC FAQ & Load Data Part III (Page 6 of 20)
Art -
Just to make it clear, I can run SSA 'combat' loads in a CMMG 6.8 barrel now? And the CMMG 6.8 bbl will still be OK with other brands of ammo too? I think this is what I am hearing from you... Bill Wiese San Jose |
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I bought the July 31st SGN issue with the 6.8 article yesterday. I didn’t get a chance to read the whole thing, just the sidebar about the Hornady ammo. I was a little confused about the fact that Hornady had been involved from the beginning. The article stated that Hornady developed the 115gr bullet that Remington uses. I thought that the 115gr bullets were advertised as Sierra MatchKings. Did I interpret this info incorrectly? Not that it matters, just wondering if anybody else has read it. Kudos to Zak for his input on the article, and of course I’d like to thank Zak for his help with getting me into 6.8mm a couple years ago. |
Hornady developed their own 115 gr OTM for the 6.8 SPC. Hornady mostlikely helped Remington design the 115 gr FMJ that Remington sells. The only comapny that I know of that produces ammo with the 115 gr SMK is Silver State, as Sierra does not make ammunition. My newest 6.8 SPC incarnation. All ways liked how the MK12 Mod 0 look. 
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I guess that I wasn’t thinking clearly, because I do have a couple boxes of Hornady 115gr HPBT bullets. Why doesn’t Hornady sell their 110gr HPBT? Could it be that they are trying to get rid of their 110gr HP flat base bullets? I’ve got a bunch of them also. I guess that I just assumed that it was the Sierra in Remington’s standard offering. According to MidwayUSA, Remington does offer a loading with the Sierra. |
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Range Report (continuation from pages 5 & 9) Ok last night I went up to the range to try out Art's suggestion of reseating the bullets to 2.185" OAL. I went up with 40 rounds of 'Combat' TMJ, and 20 rounds of the modified TMJ (I marked ever case with a M from a Sharpie). I also replaced the standard buffer in the rifle with an 'H' buffer (the H2 didn't arrive in time). First I wanted to get the scope on paper (I was using a new LaRue SPR mount - fantastic mount BTW) so I used the unmodified rounds. I needed 2 rounds at 25 yards to get the scope in the right area, then fired at a few steel plates on the hill to verify and was awarded with solid 'thuds'  .Ejection was mostly in the 4:00 area (I had a buddy watch while I shot). A couple of cases bounced off the brass deflector (and left marks) those bounced forward. At round 9 (of the factory rounds) I had a Failure-To-Eject sitation due to a primer comming out, the end of the case looked similar to the case posted on page 9, but the marks were not as deep. I should note I checked the other brass, the primers were flattened but they looked fine. Bolt was removed and I checked the chamber using the rifles Surefire. Sure enough a ring of copper was seen (and removed with the cleaning kit's bore brush). This ring wasn't as thick as the one posted on page 9 but it was one piece. At this point we stopped and set up the Chrony @ 10'. First few rounds didn't get recorded (the line of fire was too high and the sun was too low). Once I adjusted my point of aim I got the following results for the Modified Rounds: Wx: 82degF, 52% Humidty, Press: 29.97 and rising. 2605, 2642, 2646, 2610, 2657, 2639, 2624, 2600, 2633, 2641 Min: 2600, Max: 2657, Avg: 2630 SD: 57.65 I attribute the Standard Deviation to the fact the rounds had an OAL of 1.185 +/- 0.003. I learned a couple things about my press and seating bullets during this exercise and a few rounds were short (and a bit longer). There was a change in 'feel' of the rifle which surprised me, generally I'd say these rounds ran a little faster (the average was 20fps higher than the average for the 32 rounds test fired on page 5) but as a 10 shot group it was only the 2nd fastest of the 4 ten shot groups I've posted. I checked the chamber after shooting the 20 rounds (some were used to complete the zeroing of the scope). Copper was seen, but only a 'half moon' was pulled from the chamber (and it was very delicate). I noticed I had 4 rounds where there were marks on the back of the brass (the 4 rounds had MVs in the 2640 or better range). At this point I decided to stop for the night as I was out of modified rounds, and I didn't feel like pressing my good luck with the standard rounds. At this point my plan is to pull the bullets from the leftover rounds and drop the charge by 0.5gr as Art has suggested. (I could use the practice with the scale & press) Yeah I could exhange it as Art has offered, but I'd rather have the hands-on learning experience. My thanks to Fight4YourRights in helping me in this test. |
You are a glutton for punishment huh? I would take up the offer to swap the ammo. 
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Guilty
Most sane people probably would. However I don't have your experience reloading so this will give me some 'quality time' with the scale. Besides having to deal with MD UPS people about shipping items marked ORM-D can be a PITA. I'd rather deal with the scale & press rather than drive down to the UPS center and deal with a hoplophoic UPS clerk. 
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I know Randall's concern but if you are going to go forward make the powder charge 29.0 grains, weight each round charge, you will lose velocity but they should function fine. Art-SSA |
I just received my flash hider for my AAC 6.8 can for my Noveske barrel today. Had to go out and give a quick run suppressed. Only had a few OCW rounds for the quick test, but this is how it went. The sound level was very good with the 18in barrel, a big gain from my 14in barrel. The shift in POI was 3in low and 3/4 to the right. The gun is capable of shooting very well. The first two groups had called flyer's at 1.151, 1.404, and the third was right on at .415! Wish I would have had more ammo! Here are a few pic's!   Went back to the range to rezero with the suppressor and shot 10 strings of three shot groups. Discounted the smallest and largest two groups and the average was 0.681 for the three shot group. Not bad for a gas gun in a carbine platform. 
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Zak helped me with these. All reloading disclaimers apply. They shoot really well in my M1S 1 in 9.5 Barrel. I generally load it to 24.5 grains without any signs of over-pressure. 150gr Nosler BT Cartridge : 6.8 SPC Bullet : .277, 150, NOS BalTip 27150 Cartridge O.A.L. L6: 2.315 inch or 58.80 mm Barrel Length : 18.0 inch or 457.2 mm Matching Maximum Pressure: 54000 psi, or 372 MPa or a maximum loading ratio or filling of 103 % Powder type Filling/Loading Ratio Charge Vel. Prop.Burnt P max P muzz B_Time % Grains fps % psi psi ms --------------------------------- ------------------------------------------------------- Accurate No.2230 100.8 24.6 2148 96.6 54000 7029 1.090 ! Near Maximum ! |
THANKS! I will report my findings. I may venture out with a different powder too. I've loaded 130gr. Nosler BT's over 27.7gr. H335 with good results. I seated the bullet .005" back from the lands. Zak, great article! Nice Remington LTR too!
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Oh, and I load these to an overall length of 2.290. The primers are CCI large rifle primers loaded in once fired Silver State brass. Stephen |
Think about how hard it would be in New Jesery. I am all most ready to subscribe for a year, but want the garantee that I would received the July 31st issue.
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Guys, I went through the 3 threads looking for reloading data from various members. I pulled out data that specified a projectile, powder (and an amount of powder). Some of the recipes are incomplete in that they don't mention OAL nor do they tell us the MV. I'd appreciate it if you see your recipe if you could IM me with whatever extra data you could? Thanks! When complete I plan on posting this toward the beginning of the thread for people looking for load data (as the thread name suggests). Loader: stephen_101st Powder: 24.5gr Accurate #2230 Bullet: .277 Nosler 150gr BT Primer: CCI Large Rifle Brass: Silver State once fired OAL: 2.290" MV: 2220 from 16" M1S Loader: silentbushmaster Powder: 27gr RL 10X Bullet: .277 Hornady V-Max 110gr BT Primer: Remington 9 ½ Brass: Silver State OAL: ? MV: ? Loader: watersniper Powder: 30.7gr H322 Bullet: .277 Sierra 90gr OTM Primer: Federal 210 Large rifle Brass: Remington OAL: (.005 back from lands) MV: 2830fps out of 20" bolt gun. (2820 with .30 Cal Gemtech HVT can) Loader: watersniper Powder: 29.7gr H322 Bullet: .277 Speer 100gr OTM Primer: Federal 210 Large rifle Brass: Remington OAL: (.005 back from lands) MV: 2704 with .30 Cal Gemtech HVT can Loader: watersniper Powder: 29gr H322 Bullet: .277 Hornady V-Max 110gr BT Primer: Federal 210 Large rifle Brass: Remington OAL: (.005 back from lands) MV: 2640fps out of 20" bolt gun. Loader: watersniper Powder: H322 Bullet: .277 Hornady 150gr. SST Primer: Fed. 210 Large Rifle Brass: Remington OAL: (.005 back from lands, does not fit in magazine very well) Gun: 20" Bolt gun w/SRT 6.8 can Charge...............24.0 gr ...... 24.5 Velocity avg........2228...........2173 SD.......................7...............14 Loader: CaptSchofield Powder: 31.0gr AA2520 Bullet: .277 115gr Hornady & Sierra OTM Primer: Win small rifle ? Should be larger rifle ? Brass: Remington OAL: 2.295 just short enough to fit in PRI mag. MV: 2580-2600fps from 16” model #1 chrome lined Notes: have used the 110 barnes with same load as above Loader: silentbushmaster Powder: 27.0gr RL 10X Bullet: .277 Remington 115gr FMJ Primer: ? Brass: ? OAL: ? MV: ? Loader: ar15bubba Powder: 26.0gr H4198 Bullet: .277 90gr Sierra HP Primer: ? Brass: ? OAL: ? MV: ? Loader: ar15bubba Powder: 27.0gr H4198 Bullet: .277 90gr Sierra HP Primer: ? Brass: ? OAL: ? MV: ? Loader: ar15bubba Powder: 24.0gr H4198 Bullet: .277 110gr Sierra Pro Hunter Spire point Primer: ? Brass: ? OAL: ? MV: ? Loader: Sader762 Powder: Hodgden H4895 Bullet: .277 Hornady VMax 110 gr. Primer: Federal G210m Large Rifle Match Brass: Remington OAL: 2.270" Gun: 18" Randall Rausch Barrel - free floated, RRA 2-stage trigger Charge...............27.0 gr ...... 27.5 .......... 28.0 ..........28.5 ......... 29.0 Velocity avg........2260...........2280...........2317..........2328...........2421 SD......................20...............40..............28.............96...............29 Loader: Sader762 Powder: Hodgden H335 Bullet: .277 Hornady VMax 110 gr. Primer: Federal G210m Large Rifle Match Brass: Remington OAL: 2.270" Gun: 18" Randall Rausch Barrel - free floated, RRA 2-stage trigger Charge...............27.0 gr ...... 27.5 .......... 28.0 ..........28.5 ......... 29.0 Velocity avg...........2400.........2476..........2518...........2549..........2586 SD........................37..............25..............35...............30.............42 Loader: Sader762 Powder: Hodgden H322 Bullet: .277 Hornady VMax 110 gr. Primer: Federal G210m Large Rifle Match Brass: Remington OAL: 2.270" Gun: 18" Randall Rausch Barrel - free floated, RRA 2-stage trigger Charge...............27.0 gr ...... 27.5 .......... 28.0 ..........28.5 ......... 29.0..........29.2 Velocity avg..........2542..........2568...........2585..........2614.........2658...........2710 SD........................12..............7................25.............14..............17..............17 Loader: Sader762 Powder: Hodgden Varget Bullet: .277 Hornady VMax 110 gr. Primer: Federal G210m Large Rifle Match Brass: Remington OAL: 2.270" Gun: 18" Randall Rausch Barrel - free floated, RRA 2-stage trigger Charge...............27.0 gr ......28.0 .......... 29.0 Velocity avg.........2190..........2341..........2410 SD......................42...............55..............21 |
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I'm a bit curious as to what powders people have been using to reload with? I finally got around to getting some SMK's and loading them. I've used H335, H322 and H4895 with them and don't see much difference in any of the powders. My barrel does not like H335 and seems to just throw rounds everywhere with it. The SMK accuracy out of my barrel has been superb. So is there some powder that is the wonder powder for the 6.8? Just finished Zak's article this morning. Very nicely done. |
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I have the best luck with H322. I just finished testing some 150gr. Hornady SST's today. VERY accurate at 100 yards! My load consisted of: 24.5gr. of H322 .277" 150gr. Hornady SST Fed. 210 Large Rifle Primer Remington Brass Seated .005" back from the Lands in my bolt gun. W/ custom SRT 6.8 can: High= 2246 Low= 2205 ES= 41 Mean= 2228 SD= 14 This load still did not fit in the magazine very well. accuracy was under 1/2" at 100 yards for two 5 shot groups. Another promising load was: 24.0gr. of H322 .277" 150gr. Hornady SST Fed. 210 Large Rifle Primer Remington Brass Seated .005" back from the Lands in my bolt gun. W/ custom SRT 6.8 can: High= 2185 Low= 2166 ES= 19 Mean= 2173 SD= 7 Theoretically this should have been more accurate, if I did my part. It was a decent group too. Maybe the best load lies between 24 and 24.5 grains of H322? As a bonus here's some video footage of my subsonic loads. At 100 yards I had to hold 4 mil-dots high! The last shot was at a rock, you can hear the impact. Subsonic Loads |
Thanks for the load information!
I'm sure we'd all appreciate seeing the recipie for that load! That's a 6.8 supressor or a .308 supressor? |
The suppressor in the video is my custom SRT 6.8 can. The stakes are a little higher for fu**ing up this load! I'll IM you the details and you can decide, as moderator, weather to post or not. I don't want to be the reason someone blows up their gun! It's easy to forget a crucial step or try to do this without it and then blow your face off... On another note, here's two more loads that seem to work real well: .277" Sierra 90gr. HP 30.7gr. H322 Fed. 210 LR primer Remington brass Seated .005" back from the lands. Data for this load from Ohler 35P: Without Suppressor High= 2851 Low= 2809 ES= 42 Mean= 2830 SD= 16 With .30cal Gemtech HVT suppressor (flash hider bi-lock mount) High= 2845 Low= 2794 ES= 51 Mean= 2820 SD= 22 .277" 100gr. Speer HP 29.7 gr. H322 Fed. 210 LR primer Remington brass Seated .005" back from the lands. W/SRT 6.8 can: High= 2722 Low= 2679 ES= 43 Mean= 2704 SD= 17 |
What was the recipe for your subsonic round? Have you tried that subsonic round in an AR? |
All my testing was done from my 16" M1S, 1 in 9.5" upper. I don't own a chrony, but on my buddy's the highest velocity I got was 2256 fps. MV was right above 2200 (2220 if I recall). I think with a different powder I might be able to creep up on 2350 or 2400 without going nuclear. Stephen |
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Here are some of the values I got in the past: TYPICAL WARNINGS IN PLAY - USE AT YOUR OWN RISK< START LOW AND WORK UP SLOW. Loader: Sader762 Powder: Hodgden H4895 Bullet: .277 Hornady VMax 110 gr. Primer: Federal G210m Large Rifle Match Brass: Remington OAL: 2.270" Gun: 18" Randall Rausch Barrel - free floated, RRA 2-stage trigger Bench: Concrete bench using sand bags Charge...............27.0 gr ...... 27.5 .......... 28.0 ..........28.5 ......... 29.0 Velocity avg........2260...........2280...........2317..........2328...........2421 SD......................20...............40..............28.............96...............29 Loader: Sader762 Powder: Hodgden H335 Bullet: .277 Hornady VMax 110 gr. Primer: Federal G210m Large Rifle Match Brass: Remington OAL: 2.270" Gun: 18" Randall Rausch Barrel - free floated, RRA 2-stage trigger Bench: Concrete bench using sand bags Charge...............27.0 gr ...... 27.5 .......... 28.0 ..........28.5 ......... 29.0 Velocity avg...........2400.........2476..........2518...........2549..........2586 SD........................37..............25..............35...............30.............42 Loader: Sader762 Powder: Hodgden H322 Bullet: .277 Hornady VMax 110 gr. Primer: Federal G210m Large Rifle Match Brass: Remington OAL: 2.270" Gun: 18" Randall Rausch Barrel - free floated, RRA 2-stage trigger Bench: Concrete bench using sand bags Charge...............27.0 gr ...... 27.5 .......... 28.0 ..........28.5 ......... 29.0..........29.2 Velocity avg..........2542..........2568...........2585..........2614.........2658...........2710 SD........................12..............7................25.............14..............17..............17 Loader: Sader762 Powder: Hodgden Varget Bullet: .277 Hornady VMax 110 gr. Primer: Federal G210m Large Rifle Match Brass: Remington OAL: 2.270" Gun: 18" Randall Rausch Barrel - free floated, RRA 2-stage trigger Bench: Concrete bench using sand bags Charge...............27.0 gr ......28.0 .......... 29.0 Velocity avg.........2190..........2341..........2410 SD......................42...............55..............21 |
hey ya'll i did something stupid I just got my CMMG upper this week and the reloading dies came in yesterday, I loaded about 40 rounds of 6.8. the loads were: 20 rounds of hronady 115g OTM/WC H322 @ 27g new Rem. brass CCI large Rifle Primers OAL = 2.240 20rounds of the same above but with 27.6g of H322 The OAL length is the stupid part I just set the depth to fit the crimp groove. Should I be really worried about a KA-Boom. I'm goning to fire a round then check for signs but what about the first round? the factory Hornady round I have measure 2.255 with a 110g OTM. |
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You will probably be ok. Your loads are in the moderate range. I would fire & check the first 3-5 rds. for pressure. If you have a kinetic bullet puller you could pull the bullets out slightly past where you want them and re-seat. Sometimes this will affect accuracy especially when bullets have been crimped but it is better than serious problems. If you are actually concerned get a puller and do that first. Your other option if you have more brass is to just load more rounds to the correct dim. and base your decision off the results. If the pressure is fairly moderate then I doubt it will be a problem. Of course the decision is entirely yours. |
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I seriously doubt that that load is anywhere near max. Loading a bullet .030"-.050" deeper than we are typically hand loading it will not dramatically increase pressure. Shoot and check to verify that there is no noticeable signs of high pressure. Loading the bullet farther out does 2 things: (1) it seats the bullet cloaser to the lands of the barrel and in theory adds to the accuracy capability of the rifle, and (2) gives the cartridge a little more room to hold powder. This is not necessarily a problem with H322, but, other powders are "bulkier" and benefit from the added space. My .02 cents FWIW |
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WARNING USE AT YOUR OWN RISK< START LOW AND WORK UP SLOW. update: Loader: CaptSchofield Powder: 31.0gr AA2520 Bullet: .277 115gr Hornady & Sierra OTM Primer: Win large rifle Brass: Remington OAL: 2.295 just short enough to fit in PRI mag. MV: 2580-2600fps from 16” model #1 chrome lined have used the 110 barnes with same load as above Have fired approx. 600 of the above loads, sub. moa groups---always With 110 hornady spire piont have loaded up to 31.5 of AA 2520 |
Guys...I don't reload, but I am shooting the 6.8 from a Rem 700 Tac 22 in bbl. I noticed that Rem just revised down its ballistics on this round on its website. Now what is the real data on the Rem? And how about the SS FMJ data? Thx. |
SSA - from a 16" barrel - NOT A 24" barrel Vel Commercial Vel. Combat 115 FMJ 2,525 2,625 Pro - hunter 2,560 2,660 Match King 2,560 2,640 Triple Shock 2,625 2,715 Art - SSA |
This happened over a year ago. When the new loads came out, I happened to have a box and was doing a chrono session. 6.8 Chrono Session In general, they dropped 200fps across the board. |
| Bushmaster has their 6.8mm rifles and uppers listed as available. Bushmaster 6.8mm SPC |
And if they bring any parts to Camp Perry next week I might be in trouble!
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Starting at $1300? I'll pass. Especially since it appears they are using the std car gas system. |
The key word was parts... And I'd need a carbine gas system when I cut the barrel down to 12", right? This is of course for my registered SBR lower... Good point on the price, however. I won't be paying a premium because the barrel comes from Bushbastard. The word on the street was Bushy and Armalite have good deals at Camp Perry. Maybe I'm just full of shit, who knows. |
A random sampling of 3 of my 14 CProducts mags gave me 2.315" each time. I loaded up some Remington FMJs loaded to OAL of 2.22" and there was a gap of 0.115" between the tip of the bullet and the front of the mag. Looks like you'll be fine. Stephen |
Thanks. I was hoping that would be the case. Lower priced mags that will function the same, I like the thought. |
thouhgt I had that load memorized, always check you data!
Dude that is some serious AlGore, I LOVE IT! I need to get out some more with my can, now that THE MAN here says it's OK.  Same bullet over 29.0 gr. H322 for MV of 2640FPS out of the non-suppressed barrel. ETA: Note my shot has no algore. My shot was a neck shot with one little entrance and a small exit in the back. silentbushmaster had some hydrostatic damage on his. |
[ARCHIVED THREAD] - 6.8mm SPC FAQ & Load Data Part III (Page 6 of 20)
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