Range Report 7mm Creedmoor powder and velocity tests

[fireguyty]

Guys,
I have been shooting 6.5 Creedmoor in competition for about a year now. I love the round, but any improvement is tempting. I started to hear about the 7mm CM which Mark Gordon pioneered. Hearing the claimed velocities with the excellent 162 A-max sounded good to me. However, I will not stick with this case or inflate numbers just because I have made the investment.

First off, I have to thank some people. My team mates D.Miller and JFComfort for the machining. M.Gordon for the dies, and test brass. Also, Bohem and Rodent have been very helpful with load info.

Stats:
Rifle: Desert Tactical Arms SRS
Barrel: Benchmark 1-8" twist, 27.5" in length
Bullet: 162 A-max (chamber measured 2.855 COAL, all were seated to 2.850)
Case: New Hornady 6.5 Creedmoor necked up with Redding dies (Short Action Customs sells these)
Chronograph: Prochrono 10 feet from muzzle


Each day of testing I started by firing my 6.5 Creedmoor load of 41.6 g of H4350 over 139 Lapua to get a base line for where the chrono is reading. The numbers it has been spitting out are consistent with my ballistic program of 2797 FPS.

2/8/13 20 degrees, chronograph seemed to be reading a little slower today.

6.5 base line.........2772, 2772

Varget:
38.....2478
38.5.....2496, 2506, 2515
39.....2539
39.5.....2583
40.....2614
40.5.....2688
41.....2693
Notes: No signs of any pressure.

CFE223:
44.....2754
44.5.....2749
45.....2818, 2766, 2789
45.5.....2836
Notes: All primers were flat, but no other signs of pressure presented. Bolt lift very easy, no signs of e-swipe.

IMR8208XBR:
39.....2693
39.5.....2732
40.....2726
40.5.....2760
41.....2789 BLOWN PRIMER!!! Stopped.

H414:
41.....2442
41.5.....2455
42.....2501
42.5.....2534
42.9.....2564
Notes: No pressure seen.

H4350:
42.1.....2534
42.6.....2594, 2588, 2578
43.1.....2624
43.6.....2661
Notes: No pressure seen.



2/22/13 Follow up, 55 degrees.

6.5 CM base line......2801, 2795, 2801, 2795, 2801 (that seems about right for this load)

H4350: (decided to continue up to see where pressure is seen)
44.....2745
44.5.....2766
45.....2772
45.5.....2783
Notes: No pressure seen. 45, and 45.5 were compressed loads. Also the same two were through the same hole.

Power Pro 2000 MR (Federal 308 cases used)
42......wouldn't chamber
42.5.....2795
43.....wouldn't chamber
43.5.....2818
44......2855 (slightest of e-swipe)
Notes: Going to reshoot with Hornady brass.

CFE223 (reshoot higher to see where pressure is starting)
45.....2842, 2812, 2801 (.25" group!!)
46.....2873
46.5.....2911 (flat primer)
47.....2936 (Heavy bolt, stopped!!!)
Notes: Happy with group size, and velocity. I don't know what to think about the extreme spread.

AR Comp: (Federal cases)
37.....2619
38.....2715
38.5.....2710 (Heavy bolt lift, Stopped)

Varget (reshoot higher to see where pressure is starting)
40.6.....2789 (Federal brass)
40.8.....2743 (Federal brass)
41.5.....2780 (back to Hornady)
42.....2766
42.5.....2777
Notes: No pressure seen. Interesting that the Federal brass had higher velocity with lower charge.

Summary:
I had originally planned on rereaming to 7 RSAUM if this didn't work out. However, with equal velocity in a higher BC bullet than my 6.5 CM, what's not to like? From here, I am going to shoot H4350, CFE223, and 2000 MR for groups. I don't really know what to think about running CFE or 2000 MR due to temp instability issues, but the velocity is tempting. I'd be interested in anyones experience with these two powders.

 

[Mgordon]

Tyler,

I'm not sure why the Federal brass would not chamber. You may want to measure the headspace on fired brass, then check the Federal to see if the headspace is longer. Our reamer has a .317 Neck, I trimmed the brass to be in the .314-.315 range. You may also want to ensure your chamber is not tighter.

Thanks for doing this test. I wish I had time to do the same. It sounds like CFE223 is the winner!!

I am shooting Federal Brass with an average H20 case capacity of 51.6 gr internally. I believe my Hornady 7CM brass was in the 53.1 gr range. I'm shooting Varget (40.8) gr at 2745 FPS with no pressure, very stable vertical dispersion. I would really like to be in the 2800 range, CFE223 will get me there with my 28" barrel it sounds.

Mark

 

[PowerstrokeOBX]

Thanks for the test. I like where you had a control and variable, well done.

Are you going to try the 180s?

 

[fireguyty]

No, I don't think I will go up to the 180's. They are expensive, and the wind drift is not that much better inside of 1000 yards.

 

[lead ƒarmer]

Tagged for interest. I need to chose a caliber for my new S/A build...

 

[senna.bra]

I am thinking about the 7mm RSAUM as well. Tagged as well.

 

[turbo54]

Nicely done. I've been super curious to see some actual 7cm data, instead of anecdotes. Thank you.

Your results seem to indicate that just as 6.5cm is essentially equivalent (ballistically) to 260, 7cm is pretty much the same as 7-08.

Also, it looks like the PP2000 and CFE (which I understand are the same, or nearly the same) bring out the best in 7cm. I'm curious how it would work in 708.

I've found H4350 to be rather ideal in 260 and Varget ideal in 308. It stands to reason that H4350 would therefore be too slow for 708, and Varget too fast....which is precisely what I've found.

Are PP2000 and CFE double base?

FWIW, I just ordered tooling today from PTG to chamber barrels in 6.5 and 7 super LR, so we'll have that data point before too terribly long.

How was your accuracy?

 

[fireguyty]

Turbo,
I had no idea they are the same. I looked them both over, and yeah shape wise they look pretty similar double base.

I only shot groups in CFE at 45 grains, and it shot .25" at 100 yards. I intend to shoot groups as soon as I can find some more 162 A-max. That could be tomorrow, or in 6 months.

Ty

 

[CanSniper]

Tyler,

Thank you for your time and a great write up.

Your result with Varget and federal brass mirrors mine almost exactly, only I am using Lapua Palma brass. My load is 40.6 grns and runs about 2800fps. Also I seem to have ran outof case with 4350.

During load development I pushed up to 2820 with Varget which pushed me out of the node and just started to show pressure.

I settled with Varget because I have some. And I convinced my self I was going to pick a load and be happy...but now I might have to experiment some. Dang now I need to find some RL17.

 

[Cmonroe]

Tyler,

Thank you for your time and a great write up.

Your result with Varget and federal brass mirrors mine almost exactly, only I am using Lapua Palma brass. My load is 40.6 grns and runs about 2800fps. Also I seem to have ran outof case with 4350.

During load development I pushed up to 2820 with Varget which pushed me out of the node and just started to show pressure.

I settled with Varget because I have some. And I convinced my self I was going to pick a load and be happy...but now I might have to experiment some. Dang now I need to find some RL17.

Funny, I might know a guy with some RL17.

 

[7mmRM]

Interesting thread. Thanks for sharing. I've been kicking around goin from 708 to 7cm. Even made up a 7 cm dummy to send to PTG, while waiting for my 708 reamer to show up. From what I'm seeing here, Ill likely shelve the 7cm idea, as it seems there is no performance based reason and the fact Im geared up for 708 already, to make the switch.
Again thanks for taking the time to test and post.

 

[coldboremiracle]

Very interesting, Im glad to see you got them up to speed. Looks like this may be a great choice. (love the 162 Amax BTW)

 

[Onemoretime]

So are we basically saying there's no reason to go to 7cm in lieu of 7-08 period, or with 162's. I was wondering about 180's only since I have a bunch. Would it make huge difference not having the bullet seated so far down in the case as in the 7cm compared to the 7-08?

Also, I have a bunch of .308 and 7-08 dies. I also like having 7-08 loaded ammo you can pick up occasionally from Corbon and such.

 

[JFComfort]

Hmmmm... I'm going to build myself a 7mm Creedmoor now!

 

[Jedi]

Still not seeing this, no gain over 7-08

Get a push die and shove back shoulder on 284 case then blow it out ala shehane
it will run from a short action and run rings around 7-08 or this wannbe

 

[turbo54]

How about necking WSSM brass to 7mm?

Should get a 180 Berger going ~2700, fit a short action with bullet north of NSJ.

 

[CanSniper]

Did a little testing today myself. Thought I would contribute.

162 Amax, RL17, 2.850 OAL, Hornady brass, rem 9.5 primer.

43...2675
43.5...2714
44...2777
44.5...2830
45...2882
45.5...2870
46...2930
46.5...2944 compressed load and primer pocket loose.
47...2968 loose primer

Base lined standard load...2784,2790,2785.
Which is about right.
I might go back and do load development between 44.5 and 46.

 

[D Miller]

Still not seeing this, no gain over 7-08

Get a push die and shove back shoulder on 284 case then blow it out ala shehane
it will run from a short action and run rings around 7-08 or this wannbe

Lets see some numbers from your shehane. I also have 7mm non mag project im just gearing up for and considering all options. However really I dislike brass prep, reloading and fire forming so the performance gain would need to be worth the extra work.


Ty, glad to see the 7CM project starting to show some promise, the first outing was extremely disappointing. LEt me know next time you head out to test it, ill tag along if im free.

 

[Cmonroe]

The shahane runs with larger case capacities and generally speaking doesn't offer decent barrel life.

 

[Jedi]

By shoving the shoulder back ala SLR then blowing it out ala shehane
You get same case cap as standard 284 case, but it will run from S/A @ 2.950 OAL with bullet (162amax) correctly positioned in case
boat tail @ neck junction
The blown case picks up a couple grains of capacity, while the unblown would yield slightly less than standard case, so you could just shove shoulder back n skip blowing case
and still realize more case cap than 7-08 or CM, it will now run from S/A without issues with OAL of standard case
Still the 7saum does the same thing out of box but needs mag bolt face
The issue is and has been there is no good off shelf solution for S/A 7mm, no i dont consider the 7-08 a solution as it lacks case cap to provide useful fps. 284 is about min for case cap IMHO

 

[CanSniper]

The issue is and has been there is no good off shelf solution for S/A 7mm, no i dont consider the 7-08 a solution as it lacks case cap to provide useful fps. 284 is about min for case cap IMHO

I guess I dont get it. 162 AMAX @ 2700-2800fps seems to be very useful, either from 7-08 or 7CM beats a 308 hands down in ballistics and rivals it in barrel life. Also beats a 260 in barrel life and rivals or beats it in ballistics. Low recoil, good barrel life and plenty of energy on target for most big game. I like the 7CM for the ability to get the bullet close to the lands and still feed from the mag. There will always be bigger but that comes with sacrifices as well.

 

[Jedi]

How about necking WSSM brass to 7mm?

Should get a 180 Berger going ~2700, fit a short action with bullet north of NSJ.

actually thought about that, necking up 25wssm brass
but if your gonna run a mag bolt face
7saum pert much does all ya need
On a standard bolt face shoving shoulder back on 284 best solution i have come up with thus far
The gains are so nominal over current config they dont warrant expense

 

[Cmonroe]

While the 7x25wssm might be the most efficient of all the cases it is a lot of work and brass life seems to be an issue. The 7cm does achieve great velocity will consuming less powder than most s/a with a .473 bolt face and should be able to shoot past the 4500 round barrel life consuming around 45 grains per charge. My understanding from the benchrest guys is that at the 55 to 60 grain charges on the Shehane is that it's smoked by 2000 rounds, do you have knowledge otherwise? Hey, thanks to all of you who are giving data in these threads, it seems we are always balancing barrel life and performance and knowledge from real world testing is key.

 

[FCS]

7 Creedmoor offers pretty close to knee of the curve performance with minimal powder charge and runs from an unmodified AICS magazine. I started my 7 MTR project about the same time Mark did the 7 SAC, I just haven't had the time to really do much with my pet project. MTR requires forming brass and I've been a bit too busy with other things to do much of that as of late. I'm only running a 21" barrel on my MTR so I fully expect it to be a touch slower then the 7 SAC out of a 26" bbl.

I did just get my 7-08 reamer that is geared for 168 JLKs and modified AICS magazines. Once I get barrel installed and some data I'll post it up but I'm not sure the 7-08 is going to be giving up much to the 284 when OAL is 2.950" or so.

I'll have data from my 7BR project, 7 MTR project, and 7-08 project...heck, might even have Marc spin me up a 7 SAC barrel for grins n giggles.

Advantage the 7 WSSM would have is ability to run from any magazine system as a 180 is 2.780" with BT just above N/S junction. Brass would be the serious downside as it seems the WSSM brass is unobtanium right now.

 

[sakobob]

has any one tried IMR4007ssc ?seems to fall in the burn rate sweet spot of this round .
very good info fireguyty.
will be ladder testing a new SAC build this weekend (friends new toy).

 

[skeetlee]

Looks like by my numbers you could load a Berger 168 and still make 2.850 and keep the boat tail where it needs to be in the case. I'm sure help will suffer a bit but the bc on this bullet is what has my attention. Lee

 

[SporterII]

Tag, interesting.

 

[Justice1327]

Did a little testing today myself. Thought I would contribute.

162 Amax, RL17, 2.850 OAL, Hornady brass, rem 9.5 primer.

43...2675
43.5...2714
44...2777
44.5...2830
45...2882
45.5...2870
46...2930
46.5...2944 compressed load and primer pocket loose.
47...2968 loose primer

Base lined standard load...2784,2790,2785.
Which is about right.
I might go back and do load development between 44.5 and 46.

What cartridge was this? I just got my 7 mm Creedmoor back from Short Action Customs and I’m looking for a load development data.