AR15 in 6.8 spc

[7br]

I was going to wait and have a really great write up, but I am lousy at waiting. Here is what a 280412 looks like in the 6.8 spc case. Will try to post results when I get primers and range time.

[Moonie]

I'd like to know how that goes. The 6.8 is really designed with a max weight of around 115gr to 120gr.

I'm currently building an upper in 6.8 but was looking at the LBT 110gr spitzer mold.

[7br]

Justingrosche was kind enough to send me a couple other styles of bullets. Unfortunately, it will be a couple of weeks until I get to them.

[MJR007]

Interesting, I have an 6.8 and a 25wssm AR15's. I look forward to read your out come.

[bruce drake]

I don't have an upper in 6.8SPC yet but I am very interested in the progress of this thread.

I haven't ever fired a .270 or a 6.8 but the idea of a having an upper in this cartridge is starting to appeal to my desire to develop multiple uppers for my various ar lowers.

Bruce

[fourarmed]

I'm interested in that too, Mark. I have a SAECO mold and a mold for the Lyman spitzer. I'll bring some along when we get down to shoot silhouette.

[MJR007]

Well?

[9.3X62AL]

I'm getting the ducks in a row to buy an AR-15 lower receiver, and the 6.8 SPC is one of the upper ends I'll eventually get.

My understanding to date--which is not deep, by any means--is that the 6.8 SPC cartridge requires the use of a different magazine for reliable feeding. Is this the case?

Also, I recall reading in "American Rifleman" that during the time of the cartridge's development that soft-point hunting rounds were assembled for use in the deer woods, and made a good accounting for themselves on Virginia whitetails.

I will also be looking on as this thread continues, hoping to gain insight from the experiences of the good folks here.

[Moonie]

That is correct, you can't use .223/5.56 mags with 6.8, they bow out and won't seat, plus the angle is incorrect.

The 6.8 is fatter than the 5.56/.223 and the angle is very important. In 5.56/.223 you don't need the m4 ramps, in 6.8 it is almost required as the bullet/boolit is sitting deeper in the mag and needs the ramps for proper feeding. Not that they won't feed without it but they feed MUCH better with the ramps.

Geometry, who knew we actually WOULD need it as adults...

[7br]

Range time has been limited. actually non-existent. I am hoping to get out on labor day. JustinGrosche sent me about 50 280468 and 50 280473. the 468s are weighing about 119 with the check and the 473 are weight about 127. I have heat treated, checked and sized all of the bullets he sent. I have the 280412 which is going a shade over 130. The biggest limiting factor is the magazine lenth. My magazines seem to be a little picky about length and I am keeping OAL about 2.26 or so.

I am planning on trying a ladder load test. I will be loading them up on Sunday with the hopes of shooting them after the silhouette match on the 28th. I plan on using Fed sr match primers, h4895 and silver state armory cases. I will start at 23.5 gr and go up to 25gr in .1 grain increments and see if I can get three or four to group. I will take the center charge from the group and use that as a starting load. I am hoping to get velocities in the 2000fps range.

This is my first foray in the the ar15 field. My general impression so far is very positive. I think I can load it to just below .243 power for deer hunting. Recoil is very light and the accuracy is there. I got about a 1.5inch group using the sierra jword bullets with no load development.

If my boys start to shoot it, a custom mold in about 110gr might be ordered.

[GabbyM]

That big Lyman 140gr bullet you have in the photo looks pretty good.

I could send you some Loverin in 122 grain. Lyman #280468. Bullets you have look like they'd fit better but who knows. These are about the right weight. Round nose. I'm sure the gas check would be below the neck. Just have a hand full but was planning to cast a batch up from 2/6 alloy heat treated then see if I can run them 2,500 fps in my 270 Win. Over 38 to 40 grains of 4895. That bullet was made in a 110 or 114 grain size also. I see them on ebay now and then and they don't get bid on to hard. Should be able to get 2,200 fps from one.

I drew up a 6.8 SPC mould on the mountain mould site once. Think I got it to 130 or 120 gains in a flat nose bore ride design that fit flush with base of neck.

You may be surprised at how fast the 140 grain will go. I'd be very tempted to see how much RX 15 or H380 the case will hold.

[82nd airborne]

Well now that you figured it out, I guess I'll have to run a group buy of Cast Boolit special edition 6.8spc uppers!

[82nd airborne]

I wrote an article on the titled "Terminal Ballistics of the 6.8SPC in the Field" which was a few pages covering load data, ballistics, as well as results on live game, and, well other live stuff shot with the 6.8. Maybe I can find it and post here.

[justingrosche]

82nd ABN, I cant seem to get your link to to work , would you please list the WWW. addy?
Thanks
Justin

[dk17hmr]

I got chewed out a couple years ago for using my 6.8 SPC with 110gr V-Max on whitetails in Michigan.......but
http://i48.photobucket.com/albums/f208/dk17hmr/Dougs9point2008.jpg

If it were to use it on anything bigger I would go with the Nosler Accubonds.

I had some, might still have them, 120ish grain cast hollow points. The heavier bullets work really good for subsonic cat thumpers, dont expect the action to cycle though.

[82nd airborne]

Justin, the one in my sig line?

[MJR007]

My 6.8 likes 110gr ProHunters with Reloader7. It is the perfect kid combo for deer.

[7br]

Little bit of an update.

The 280473 averaged 128.2 gr for three boolits. 280468 averaged 119.4 for three and the 280412 averaged 143.4 for three boolits. I will have to rethink the load on this one. The 280468 functions in the magazine at a longer oal than will chamber.

I have had a wild hair for an ar15 for a while. I really couldn't justify a .223, but I saw what a 6.8 did to a large whitetail doe and decided it would work for a deer rifle. Now it is justified.

New Pictures:

[7br]

New Pictures

[9.3X62AL]

DK--

Uh, that seems to have worked just fine, as-is.

[7br]

I managed to sneak out the range range last night with my 15yo son and one of his buddies. We shot up most of the ammo I had loaded with little hard data collected. Most of our shooting was done at 50 yards. As I expected, lighter boolits or go faster seems to be the rule.

All loads were with Fed SR match primers, H4895, off of bags at 50 yards.

I shot two groups with the

280412 - 143 gr water dropped
25.0gr - 2" group
22.5gr - 3 3/4" group

280473 - 128gr oven heat treated
24.5gr - 4" with 4 in 2"
24.0gr - 3 1/2" with 4 in a 1 1/2" wide x 1/2 high group
23.5gr - 4" group

280468 - 119gr oven heat treated
23.5gr - 3" group with 4 in 1 1/2 group, 3 in a horizontal line 1" wide
24.0gr - 2 3/4" group
25.0gr - 4shot group. 4.5" group. Taking out 1 flyer, left a 3/4" group for the other three.

With a combination of me and the boys firing the groups, I can only give impressions. Lighter and faster seems to be the rule with the 1 in 11 twist. Anyone want to trade me for a 280468 for a single cavity 280412???

I ran about 70 rounds of assorted cast and jacketed. When I got home, I drug a couple of patches soaked with Ed's red through the barrel. No leading that I could tell. Just powder residue. Thank you Buckshot for make a dead nuts on sizer die.

The primers looked nice and rounded with no pressure signs. The rims did have a couple of shiny spots. I seem to remember reading somewhere that this could be a sign of pressure, but I can't remember.

As far as jacketed goes, we will just say that any deer within 250yards better have its life insurance paid up.

[justingrosche]

82nd, got it work that time. Looks like you have some interesting projects in the works.
Justin

[justingrosche]

7br, I'm glad you had some positive results with the Boolits. I wonder how 468 and 473 would do cast with Lino.
Justin

[GabbyM]

on the #280412 what size are the noses? Can't help but wonder if they are enough under .270" to account for not doing as well as the Loverin bullets.

[82nd airborne]

82nd, got it work that time. Looks like you have some interesting projects in the works.
Justin

Thank you sir, the website is under construction, at the present time it is only about 1/3 of the way done, if that. My web designer is having a baby, may be a couple weeks before we get it finished. Ive heard that can be incapacitating.
Aaron

[7br]

on the #280412 what size are the noses? Can't help but wonder if they are enough under .270" to account for not doing as well as the Loverin bullets.
Food for thought. The noses are mic'ing at .266. I can drop a bullet in from chamber and muzzle and get a lot of wiggle. No marks from the rifling anywhere.

[GabbyM]

Sounds loose to me although I'm no expert at shooting undersized noses. You might try Beagaling the bottom of the mould to see what kind of nose you can get out of it. I'd bet my money on the small nose being the reason your Loverin out shoots it rather than the weight difference. I'd be completely shocked if an 11 twist barrel would not stabilize that 142 grain RN bullet. Seams to me if you got the nose to fit and dropped down to a slower powder like 4064 , WW760 , RL15 or 17 maybe even some H4831 you could get that heavy slug going downrange with a thump. Although that is a pretty big boolit for that sized case.

I drew a bore ride BTAN up on Mountain moulds the other day. It came out at 120 grains with 91/3/6 alloy. Looking at the 6.8 SPC load data it appears a 40K psi load would be at or under 2,300 fps with a 120 grain cast boolit. Then I drew up a 110 grain boolit that looked interesting. One would think we could run a 110 up to 2400 fps. We all just need a guinea pig to try this stuff out on. 110 may sound like a light bullet but if we can shoot it as fast as we can shoot the 55 grain 22 caliber bullets then we've taken a huge leap up in power. Then for plinking around a 2000 fps load would be easy on barrels. However for plinking I'm pretty happy with my 223's.

[7br]

More load testing after the silhouette match at 50 yards off of bags. My buddy put 4 jword bullets in 1/2 in at 50.

The 280473 seems to be working fairly well. For reference on target pics, the black is a smudge under 1.5inch.

I have a 135gr LBT mold for my 7mm xp100. For giggles I sized a boolit down to .278 and lookit what I got. It will chamber with very light rifling marks just below where the nose goes tangent to the body of the bullet. The picture shows an unsized boolit about the dummy round, a sized boolit below the round and 280473 for comparison on the bottom.

[7br]

Got to the range tonight. The 7mm sized to 6.8 did not work very well. Did recieve a care package from JamielovesJammie. He sent the light 280468 and a modern bond bullets. Along with two or three other styles. Unfortunately, it is going to be about 2 weeks until I can get powder.

[hicard]

82nd airborn. I wish you would design a .278 bullet around 120 grs designed just for the 6.8 having a gc hp. I would be very interested in one.

[Moonie]

hrm, Mihec cramer work of art?? I'd be down for that, just a thought.

[82nd airborne]

My bullet design is fairly limited, but I bet I know someone who could, maybe I can go twist his arm....

[7br]

I would be up for a group buy, but I would like to speriment a little more. Give me three weeks to see how lighter boolits work. I am thinking more of the 105-115gr range. I would like a flat nose gc design. Not to terribly interested in the hp, but if there were a pin for plain nose, I wouldn't bark.

[7br]

Thanks to JameslovesJammie, I have three lighter boolits to test. The Lee 270-110, a modern bond at about 105gr and the light 280412. I haven't been able to get the checks seated on the bond boolit as well as I would like. I am about out of 4895, so only loaded up 5 of the light 280468 and 5 of the lee boolits. Unfortunately, I managed to shave lead on one side of one 280468 and one of the lee boolits. I wound up shooting 4 shot groups at 50 yards and here are the results. The rings on the targets are spaced 1 in apart. The powder was 25 gr 4895. Target on left is the light 280468, target on right is the lee boolit.

[Moonie]

I was unaware that Lee made a 270 mold, more info please?

edit: nvm, found it, old out of production single cavity.

[7br]

Doesn't it stink. Find a boolit that is working from an inexpensive mold and I can't get one.

[jameslovesjammie]

Wow! I'd take the Lee group any day! I wish the gas checks would have fit the Modern Bond bullet better. I really thought that design would have been a winner. Were the checks too tight or loose?

[7br]

James,
The checks on the Modern bond were too tight. Tried opening the checks up with a large ball bearing, but could not get them to seat square. I think they would have been great if I could have gotten the checks on them. You wouldn't want to sell/trade the light lee mold would you? I might have to pony up the money and go over to Mountain Molds and have something similiar made. $85 would be about 400 of the Sierra 110 pro hunters, so I think I can justify the purchase. I'll just tell my wife that the rifle gives me excellent bonding time with the kids.

I am helping with the Lake Afton Clinic this weekend, so it is going to be a couple of weeks before I get back to the range. Will definitely shoot more than a couple of four shot groups then.

[GabbyM]

7br: Have any ideas on why the 480468 laid down two separate groups?
I'm wondering if it isn't a bore conditioning issue. Could you see if they hit in one group then moved over and stayed there. Since it's not unusual to need a few fouling shots be fore a group settles in. Not ideal but not unusual. Hard for me to imagine a Loverin that won't shoot.

I have an old AR with standard non free floated service rifle stocks. One of the noodle barrels to boot. I can make the bullet move a couple inches at 100 just from sling tension when in a position. I shoot that rifle with no sling tension and just listen to people tell me how I'm doing it all wrong. Then some rifles will shoot a round or two into a cold barrel group then shift POI when the barrel heats up. Not heard much about AR's doing that but they may not be immune to it. Problem with a free float tube on an AR is they add a lot of weight.

[7br]

Gabby,
The far right shot on the 468 was the third shot. I was having trouble with the first shot of a string throwing wide left. That seems to be going away. I could have flinched or I might have changed the bags, my hold, ie, shooter error. I will try to pick up some 4895 and load some up. Might be able to sneak to the range during next week.

[uncle joe]

I got chewed out a couple years ago for using my 6.8 SPC with 110gr V-Max on whitetails in Michigan.......but
http://i48.photobucket.com/albums/f208/dk17hmr/Dougs9point2008.jpg

If it were to use it on anything bigger I would go with the Nosler Accubonds.

I had some, might still have them, 120ish grain cast hollow points. The heavier bullets work really good for subsonic cat thumpers, dont expect the action to cycle though.

thanks for the post Doug, I bought a stag upper in 6.8 that looks just like the one in the pic, during my recuperation I'm having to leave the 7 mag in the cabinet and needed something with a little less recoil for deer this year. I've been wondering how the 6.8 would do and you have revived my faith. hope to see some good data here so I can start casting for it.

[uncle joe]

I wrote an article on the titled "Terminal Ballistics of the 6.8SPC in the Field" which was a few pages covering load data, ballistics, as well as results on live game, and, well other live stuff shot with the 6.8. Maybe I can find it and post here.

82nd. I would love to read the article, trying to find all I can on the 6.8, it's so new to regular folks like us that there's not much info about it.

[jameslovesjammie]

Mark,

Sorry, but I can't let the Lee mould go. I collect .27 cal moulds. I have the following moulds:

Lyman/Ideal
280411, 280412 (factory HP), 280468-S, 280468-L, 280473, 280642

RCBS
270-130-FN, 270-150-SP

Saeco
270

Lee
C-277-125-R, C-270-110-R

Cramer
B2, B3

Ohaus
Don't remember number but looks identical to the 280468

Modern Bond
B-280780

I'd really like to get the Bond A-280902 and Cramer B1. I saw a B4 on Ebay once, but the guy didn't know for sure if it was a .277 or .284 cal. I should have just got it, as it would work either way. The H&G moulds seem to have vanished into thin air, and I don't know if I could afford one if I did manage to find one.

[82nd airborne]

Uncle Joe, Ill try to dig it up and post it or email it to you. Keep in mind it was not written for people with the same level of ballistics knowlege as can be found on this site. It is mainly a few loads, data on how they performed, and how they do in the field on live test subjects.

[7br]

Got to the range yesterday. Shot the lee 277-110r with 25gr of 4895. Was getting 4" patterns at 50 yards. Heck, I was doing that standing with my Dan Wesson. JBullets were going into 1 1/2" at 100.

Anyone with different powder ideas? Should I go lighter? Switch powders? Give up and stick with pistols like the good Lord intended me to do?

I did notice that sometimes the noses got damaged during feeding, so I left the magazine in the rifle and loaded directly into the chamber. Still got no Joy.

[Moonie]

Personally I'd go with a different powder for 6.8. Don't get me wrong, I load H4895 in lots of things and love it but for 6.8 the powders of choice for the heavier bullets are 335 and Reloader 10x. Lots of guys use 322 as well but it is a little faster than the others.

I've only found 1 load for H4895 and the velocity was VERY low compared to all other powders. I would look into R10x myself.

[MakeMineA10mm]

Gabby -- What do you think of a .277" version of the Saeco 315 boolit mould? It's kind of a cross between a Loverin and a bore-rider-nose design, since the forward bands are tapered so much... Seat it out as far as the mag allows, and adjust the forward (skinnier) driving bands, so they bore-ride? Put the one drive band between the nose and full-diameter body at about .001" smaller than throat diameter? Make the bottom two drive bands and gas check shank so that all but the bottom half of the gas check sit within the neck when loaded...

No doubt this would feed perfectly fine, and I would think it would shoot, but what are your thoughts?

[7br]

I've only found 1 load for H4895 and the velocity was VERY low compared to all other powders. I would look into R10x myself.

I was actually wanting the lower velocity. My thinking was the 4895 would give me good loading densities. I tried 322 and it did not work very well either. Might be time to sip on a barley pop and consider what I should do next.

[Moonie]

7br, I do understand the desire for the loading density and H4895 is my go to powder for several calibers. I will probably try it myself in my 6.8 once I start playing with cast in it.

[7br]

I was having to seat the 280468S at 2.020 to get the round to chamber. Today, I was loading some up and now can seat them out to 2.190. I gave the rifle a good cleaning. I also sized the loverin bullet all the way to the last band. The bolt closes all of the way and I don't have to hold on to the charging handle and bounce the butt on the ground to unchamber a round. I have light rifling marks on the nose.

Any ideas on what gives now?

Got to get back to the range.

[Moonie]

I'm having a similar issue with my AR with a 5.56 upper. I'm thinking an issue with brass rather than the boolit.

Testing the rifle with the bator went very well, when I went into production I added the crimp die to the equation and cycling went to hell. Bolt wouldn't seat about 25% of the time and had to do the butt bounce to get the bolt open.

I found the boolits were seated too long so I reseated them shorter. Now I know the boolits are deep enough but still having issues, now down to 10% of the time. Seating the boolits deeper did pull up a ring of lead but I'm thinking either crimping or reseating may have bulged the case somewhere. Time to pull all the boolits and start over, ugh, over 300 of them I believe.

[7br]

Did not think of case issues. I was expanding the case mouth with a punch.

Are you using the lyman M-die? This is the first batch since I got the .27 mandrel for my m die. Are the noses of your boolits engraving?

I do have the rcbs mould and could send you some 55grain boolits your way. By the way, the offer isn't out of kindness. In a couple of years, I am hoping to get a .223 upper.

[Moonie]

I am not using the m die yet, using the Lee universal to flair.

Before I reseated them they were engraving badly and causing issues, after setting them deeper they are not engraving but still having chambering issues.

PM me, I'd love to try some of the rcbs boolits there is actually a group buy going for a clone of this boolit I believe, thinking about a 4 cav of it.

[45 2.1]

Take a look.
http://castboolits.gunloads.com/showthread.php?p=1096451#post1096451

[Moonie]

Yea, saw that yesterday, great idea and I'm all for it, did just post some important chamber information in the thread.

[Russel Nash]

I don't know if this will help or not, but this article by Zak Smith is on the 6.8 :

http://demigodllc.com/articles/6.8-mm-spc-cartridge-history-development-hornady-stag-arms-carbine/

chances are if there is any load data in there it will be with those j-word bullets.

Zak really knows his stuff, so the other articles he has posted up might be informative too.

[7br]

One of my new years resolution is to shoot more, so to get the year off right, I went to the range. The 280468S gave me three 2" groups at 50 yards. I will start trying to tweek the load and see where it will go. Temps were in the mid 20's after about 25-30 rounds, the bolt would not go fully into battery. I wound up having to bump the forward assist with more enthusiasm than I would like. Not sure if I am over lubing the rifle, or if the load is gunking it up. I had 5 rounds that refused to go into battery. After cleaning the rifle, They would. Also, it took me about 20 minutes to get the barrel clean. I thought that was a little much as I only shot about 50 rounds.

Thoughts, ideas?

[jameslovesjammie]

Mark,

Are you using LLA on that Loverin design? If you are, you may want to consider dip lubing instead of tumble lubing. This may keep some gunk from building up on the feed ramp and make it easier for successive rounds to chamber. Just a thought.

James

[timbuck]

I wrote an article on the titled "Terminal Ballistics of the 6.8SPC in the Field" which was a few pages covering load data, ballistics, as well as results on live game, and, well other live stuff shot with the 6.8. Maybe I can find it and post here.

Did you post this somewhere. i have this one also and would be interested.
Thanks

[82nd airborne]

No, I actually forgot I wrote the above after a short search for the article! Sorry about that all, I will write it down this time and see what I can do.

[7br]

Got to the range today. Loaded up rounds at 1gr of 4895 increments starting at 21 going to 25 grains. Shot one 5 shot group of each load at 50 yards.

wt width height total
21gr --- --- 2 1/4 in. Round group
22gr 0.75in 2.00in 2.25in
23gr 0.75in 2.50in 2.50in
24gr 1.00in 1.25 1.50in
25gr 1.50in 0.75 1.50n.

Think I may go up from here. Did have trouble feeding some rounds. I will check adjustment on dies and make sure I am full length sizing. Cases are coming out pretty dirty with some carbon about midway down on the shoulder.

I did start using an m-die and sizing the boolits to the last groove. Also seating them out longer. I am about out of Javelina lube. I have Thompson Blue angel pushing it out. I should be sizing a bunch of .45 acp soon, so I will see how the thompson holds up.

Thoughts or directions to go?

[Russel Nash]

what kinda velocities are you getting?

[7br]

I have not chronographed my cast loads. Just guestimating, I would say arount 1900 fps. With a 110 sierra, I am getting right at 2800 fps with close to max H322.

[morme@gte.net]

Are you guys aware of the group buy for the Lee 110gn plus 125gn duplex mold?

http://gunloads.com/castboolits/showthread.php?p=1229775

[Good Cheer]

The Lyman 280473 looks like a skim cut across the top of the blocks to put the gas check closer to the neck and a pin installed to make a little shorter ogive might be worth while.
How big of a flat could it have on the nose and still feed OK? Very much?

[morme@gte.net]

Just got back from the range. I shot all the bullets previously listed.

Quick conclusion
Lee C277-125R with 23 grains RL 10X was by far the best performer. Next was either the Lee C285-130R sized to 278 with the same load, or the RCBS 27-130-FN also with 23 grains RL10X.

The Lee 7mm Soup Can was the worst. I could only hit the 12" steel plate 75% of the time at 100 yards. I would say it had 12" or larger groups. Neither of the old Lyman bullets did well (with RL10X), either the 280473 or the 280468.

Here are pix of the targets I took with my cell. Note, my reference shots was a 3 shot group of factory SSA 100gn SP (Nosler white tip) bullets. The target shows my first 3 (cold bore) shots. Rings are 1/2 inch apart.

SSA Refererencehttp://castboolits.gunloads.com/imagehosting/thum_109504ddde41121822.jpg (http://castboolits.gunloads.com/vbimghost.php?do=displayimg&imgid=965)


C277-125R 100 yds 23gns RL10X 1.05" center to center http://castboolits.gunloads.com/imagehosting/thum_109504ddde432d65fe.jpg (http://castboolits.gunloads.com/vbimghost.php?do=displayimg&imgid=966)


Lyman 280473 100 yds 23gn RL10Xhttp://castboolits.gunloads.com/imagehosting/thum_109504ddde479e9485.jpg (http://castboolits.gunloads.com/vbimghost.php?do=displayimg&imgid=967)


RCBS 27-130-FN 100 yds 23gn RL10Xhttp://castboolits.gunloads.com/imagehosting/thum_109504ddde4acb20cc.jpg (http://castboolits.gunloads.com/vbimghost.php?do=displayimg&imgid=968)


RCBS 27-130-FN 50yds 21.5gn RL10Xhttp://castboolits.gunloads.com/imagehosting/thum_109504ddde4d4b0ef5.jpg (http://castboolits.gunloads.com/vbimghost.php?do=displayimg&imgid=969)


C277-125R 50 yds 23gn RL10Xhttp://castboolits.gunloads.com/imagehosting/thum_109504ddde50fc8abb.jpg (http://castboolits.gunloads.com/vbimghost.php?do=displayimg&imgid=970)


RCBS 27-130-FN 100 yds 23gn RL10Xhttp://castboolits.gunloads.com/imagehosting/thum_109504ddde56ca6067.jpg (http://castboolits.gunloads.com/vbimghost.php?do=displayimg&imgid=971)

[7br]

Can you give particulars on your firearm? Kinda interested in gas system length.

[morme@gte.net]

Standard carbine 16" barrel. SPCII throat. bullets seated to magazine length, which is .010 off lands in my gun. I used a stoney point case length gauge.