when you say, standard you mean factory off the shelf type rifle? I ask because I just received a 7-08 today and will be looking for load info.
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7mm Options in AI AT or SA AICS rifle?
- Thread starter Glassaholic
- Start date
Simple kinetic energy vs momentum. Velocity or retained velocity makes kinetic energy look good but it’s not everything.
Stole this from the internet because I’m lazy.
Momentum and kinetic energy are each always completely linked to the velocity of a moving object, so if you know the (relative) velocity and mass of an object then you always can calculate both, with KE increasing in quadratic fashion with respect to velocity increases while momentum merely grows with parallel linearity.
The momentum presents a truer picture of the striking "force" of an object, while the kinetic energy reflects how long that force will be applied in said collision if it is one that is not completely elastic.
Mine is a custom rifle chambered with a saami reamer. The barrel is a high quality match grade barrel but the chamber is saami. I'm using starline.308 small rifle primer brass and run it through a full length sized and trim to SAAMI length.
Sorry for the delayed replies, hectic day.
My data hasn't changed from the 7mm SAW thread but just to collate it here:
My current load is 46gr of RL16 with a 160TMK which hits 2820 (proof carbon) and 2842 (proof steel). I use the same load for now for both (OAL is 2.945" I think, will need to check my notes) I suspect I have slow barrels as well. I have had decent results with the 162 ELD-M, the X's weren't so flash. I've had ELD-Ms fall apart on me though and the plastic tips are so easily damaged. I am yet to have this issue with the 160TMK.
Projectiles from Left: 162 ELD-X, 162 ELD-M, 160TMK, 175 Elite Hunter, 183 SMK.
The node seems to cover both rifles, from around 2800 - 2865 or so with grouping sizes similar throughout that range. Going back through my notes, I had some tiny groups with 46.2gr of RL16 and ELD-Ms.
Of interest, I've run ball powder (MR2000) using the Berger 175gr elite hunter. I had some ridiculous velocities (up to 2920fps) but found it to be very temperature sensitive and somewhat concerning with pressure on a warmer day.
Of note: I think the SAW type 1 reamer is a bit of a let down unless you're going to run a 150gr projectile. If you're going to get a SAW chambered, just get the type 2. My results are based around a type 1 reamer that has had the freebore extended to 0.100". Clayton saw 2816fps with 45.0gr of RL16 with the 160TMK.
Starting load data I was sent by Clayton is as follows (for 160TMK/162ELD):
Varget/AR2208: 40.5gr
H4350/AR2209: 43.5gr
Reloader 16: 43.5gr
This is a mockup of a 7mm Creedmoor vs 7mm SAW:
This is the 6.5 SLR flanking a 7mm SAW:
Edited to add: If I can find a 308 SRP bolt for my AXMC here, I'll chamber a barrel in 7mm SAW for it.
My data hasn't changed from the 7mm SAW thread but just to collate it here:
My current load is 46gr of RL16 with a 160TMK which hits 2820 (proof carbon) and 2842 (proof steel). I use the same load for now for both (OAL is 2.945" I think, will need to check my notes) I suspect I have slow barrels as well. I have had decent results with the 162 ELD-M, the X's weren't so flash. I've had ELD-Ms fall apart on me though and the plastic tips are so easily damaged. I am yet to have this issue with the 160TMK.
Projectiles from Left: 162 ELD-X, 162 ELD-M, 160TMK, 175 Elite Hunter, 183 SMK.
The node seems to cover both rifles, from around 2800 - 2865 or so with grouping sizes similar throughout that range. Going back through my notes, I had some tiny groups with 46.2gr of RL16 and ELD-Ms.
Of interest, I've run ball powder (MR2000) using the Berger 175gr elite hunter. I had some ridiculous velocities (up to 2920fps) but found it to be very temperature sensitive and somewhat concerning with pressure on a warmer day.
Of note: I think the SAW type 1 reamer is a bit of a let down unless you're going to run a 150gr projectile. If you're going to get a SAW chambered, just get the type 2. My results are based around a type 1 reamer that has had the freebore extended to 0.100". Clayton saw 2816fps with 45.0gr of RL16 with the 160TMK.
Starting load data I was sent by Clayton is as follows (for 160TMK/162ELD):
Varget/AR2208: 40.5gr
H4350/AR2209: 43.5gr
Reloader 16: 43.5gr
This is a mockup of a 7mm Creedmoor vs 7mm SAW:
This is the 6.5 SLR flanking a 7mm SAW:
Edited to add: If I can find a 308 SRP bolt for my AXMC here, I'll chamber a barrel in 7mm SAW for it.
@wjm308, sounds like a cool project with the AT, I haven’t run all the numbers but it might be worth looking at a 7mm-08 Ackley Improved .
Lapua brass you just have to fireform once and you get 7mm goodness with decent velocity. Not sure if 160’s or 180’s would be best, you’d have to compare numbers. That would be cheaper than a $1k bolt. 7mm-08 is a honey of a cartridge that’s been overlooked a long time from what I hear.
I just got a 7 SAUM pre-fit for my short action but I have changeable bolt heads.
The 25 CM might be worth a hard look too, like you said. Berger’s doing a .25 boolit soon supposedly.
Lapua brass you just have to fireform once and you get 7mm goodness with decent velocity. Not sure if 160’s or 180’s would be best, you’d have to compare numbers. That would be cheaper than a $1k bolt. 7mm-08 is a honey of a cartridge that’s been overlooked a long time from what I hear.
I just got a 7 SAUM pre-fit for my short action but I have changeable bolt heads.
The 25 CM might be worth a hard look too, like you said. Berger’s doing a .25 boolit soon supposedly.
@Simia Dei
What was the reason you stopped pursuing the 175gr and 183gr projectiles?
Seem's like most guys are opting for the 160ish gr bullets despite the heavier ones sacrificing very little velocity.
What was the reason you stopped pursuing the 175gr and 183gr projectiles?
Seem's like most guys are opting for the 160ish gr bullets despite the heavier ones sacrificing very little velocity.
No reason beyond having already purchased a shitload of 160s. The 183s would only be worth pursuing if you single feed, they are bloody long.
I've been shooting a 708ai for a while now. As someone mentioned up thread, Staball 6.5 is kind of pixie dust. Current load is:
Lapua 708 brass fireformed.
162 Amax (still have a bunch ha)
Fed 210m
49.1 Staball
2.95 coal
2945 fps SD 6.5
26" barrel
I went up to 50.2gr and was just starting to see light ejector swipe marks.
One of the nice things about the 708ai is you can buy any box of 708 and go out and shoot it. In fact I started by working up a 708 load like usual, and then started stacking fireformed brass.
Lapua 708 brass fireformed.
162 Amax (still have a bunch ha)
Fed 210m
49.1 Staball
2.95 coal
2945 fps SD 6.5
26" barrel
I went up to 50.2gr and was just starting to see light ejector swipe marks.
One of the nice things about the 708ai is you can buy any box of 708 and go out and shoot it. In fact I started by working up a 708 load like usual, and then started stacking fireformed brass.
Funny to see one of my old, neglected, threads referenced above. The last great shortage had me working with what I could get. Reamers and barrels were more available than popuar components, so I played with the WSSM since its unpopularity meant brass was available. Later, even that dried up as it was not worth the maker's time to produce any new brass with high demand for .308-based cartridges.
Pretty much no max mag OAL in SA AICS pattern magazines.
162s at 2950
175/180s at about 2850
183SMK/185RDFs a little above 2800 depending on how hard you want to lean on it.
Yes, there's some cherry picking and prep for brass, but I get 25-30 reloads on it, and it's not too big a chore when you have the tools to make it easy.
6.5Staball would be a nice candidate to try too, maybe IMR4451, or VV555.
162AMAX
L to R: 185RDF 175SMK 180HYB and a 200yd group with zero load workup on the RDF; just backed it off .5gr and shot 6.
Pretty much no max mag OAL in SA AICS pattern magazines.
162s at 2950
175/180s at about 2850
183SMK/185RDFs a little above 2800 depending on how hard you want to lean on it.
Yes, there's some cherry picking and prep for brass, but I get 25-30 reloads on it, and it's not too big a chore when you have the tools to make it easy.
6.5Staball would be a nice candidate to try too, maybe IMR4451, or VV555.
162AMAX
L to R: 185RDF 175SMK 180HYB and a 200yd group with zero load workup on the RDF; just backed it off .5gr and shot 6.
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That's what I thought when I drew up a case comparison. It is very refreshing not to have to dance around the ~2.965" max mag length. So far as I know, there's no 7mm commercial equivalent used for short actions. The Bartlein barrel's still ~.5MOA after nearly 2000 rounds.
@wjm308, if the component shortages and threat of wildcatting hasn't scared you off, you might consider a stubby .284 Win with the shoulder pushed back. Lapua's dangling that carrot out there offering .284 Win brass. In the grand scheme, the initial investment in reamers and dies is cheaper than the components it'd take to burn out a barrel. In my opinion, a case with ~55gr of water capacity will get you heavy projectiles well past 1000yds super sonic and will work well with things between H4350 to H4831 burn rates. You'll get pretty respectable barrel life compared to various 7mm "magnums" too.
Such a cute cartridge!Funny to see one of my old, neglected, threads referenced above. The last great shortage had me working with what I could get. Reamers and barrels were more available than popuar components, so I played with the WSSM since its unpopularity meant brass was available. Later, even that dried up as it was not worth the maker's time to produce any new brass with high demand for .308-based cartridges.
Pretty much no max mag OAL in SA AICS pattern magazines.
162s at 2950
175/180s at about 2850
183SMK/185RDFs a little above 2800 depending on how hard you want to lean on it.
Yes, there's some cherry picking and prep for brass, but I get 25-30 reloads on it, and it's not too big a chore when you have the tools to make it easy.
6.5Staball would be a nice candidate to try too, maybe IMR4451, or VV555.
162AMAX
L to R: 185RDF 175SMK 180HYB and a 200yd group with zero load workup on the RDF; just backed it off .5gr and shot 6.
Those 185 RDF’s shoot!
That’s impressive speed for a 7mm-08 standard bolt face even Ackleyized! The 162 ELD-X has a G1 of .630, and 2900 is Rem mag factory ammo velocity.
Testing has shown that staball to be fairly temp insensitive, not as good as Hodgdon Extreme but still good. I wonder what speeds you could get out of a standard 7mm-08 with Staball or H1000,H4350?
For OP, I’d be looking hard at the 7mm-08 standard or improved. That or the 25 CM is going to be your best bet for ELR. You’ll see more splash with the 7mm stuff. PVA solids could pump up your numbers too. Just get a proper twist for them when you buy your barrel.
What would a 7 CM give you that a 7mm-08 wouldn’t? Shorter OAL?
To me the 08 makes more sense because there’s lots of good factory ammo plus Lapua brass.
A better fit in AR mags.
I won’t argue that 7-08 isn’t perfectly fine as is.
Just commenting on those in the CM fad.
Ok, I figured it would just be length. I guess if someone really wanted a 7mm AR10 but in a bolt gun I’m not sure the juice would be worth the squeeze doing a 7 CM. Some guys just love to tinker and it’s interesting sometimes. With two young kids I just don’t have the time or money to go too deep into the rabbit hole for marginal improvements. Glad others do, guys like @reubenski and you add a lot of great info to threads like this.
Dorgan Trostel finished top ten(first in light class I think?) at the Hornady precision hunter steel challenge we shot in with a straight 7mm-08. Light class meant the whole rifle with scope, mag and bipod was under 12 lbs.
I shot a straight 6.5 CM in light class but was not in the top ten, lol. Most guys just stripped down their match guns to be under 16 lbs in open class.
I’m going to run a 7saum for the NF ELR match this year, I’m hoping to get decent velocities with mag length 180 Bergers in a short action.
Hornady bullets were blowing up a lot on people in the saums and PRC’s. That match made a lot of Berger fans I think, lol.
Sorry for the random thoughts, long story short; 7mm interest is up and I think it’s great
7mm IHMSA has been around for decades and is basically what a 7mm CM would be. Just run 300 savage through a full length ihmsa sizer die and your done.
Do they have a website for the NF ELR Steel Challenge? I'm not on Facebook but that's all I can find for info. Also, is Scott Satterlee going to do the Hornady Hunter challenge again, I'm in Colorado and wished it would have worked out for the Grand Junction shoot.
Just so you know, my Bighorn SA 7 SAUM with 26" barrel is pushing Sierra 180 SMK's at 2974 with Alpha WSM AICS magazines. Berger 180's weren't far behind but a few fps less with Reloder 25. I now have some Re26 and really curious to see what I can get out of it, going to try some Berger 184's as well. My barrel is a 1:9 and stabilizes the 180's just fine.
@wjm308, yes Scott will be doing both those matches again as far as I know. I’ll PM you the info from FB that’s up so far, they were awesome matches!
Sounds like our 7saums will be almost identical, mine is on an Origin and a 24” or 26” CF Proof Pre-fit, can’t remember length off hand right now.
I’m hoping I can get decent velocity with H1000 since I have a bunch of it and it’s temp stable. RL26 is supposedly a bit better for speed in those but was hard to find before the great components drought started and is like unicorn farts now. Anything 2850 fps+ with the 180 Berger’s and mild pressure and I’ll be happy if it had good SD/ES. Consistency was way more important in ELR than raw ballistics in the NF match, even with 40-60 mph winds we had last year! I’m still finding WY moon dust in cracks and crevices.
Sounds like our 7saums will be almost identical, mine is on an Origin and a 24” or 26” CF Proof Pre-fit, can’t remember length off hand right now.
I’m hoping I can get decent velocity with H1000 since I have a bunch of it and it’s temp stable. RL26 is supposedly a bit better for speed in those but was hard to find before the great components drought started and is like unicorn farts now. Anything 2850 fps+ with the 180 Berger’s and mild pressure and I’ll be happy if it had good SD/ES. Consistency was way more important in ELR than raw ballistics in the NF match, even with 40-60 mph winds we had last year! I’m still finding WY moon dust in cracks and crevices.
thanks verd, I’d appreciate the info. I use H1000 with the ELD-X 175’s and settled on 2932 for those with the best ES/SD I could muster, will have to open my LD book to see exactly. But I hear you on getting best ES/SD rather than speed for long range accuracy/consistency. @NoLegs24 won last years NF ELR with a 300 Norma, my buddy shoots a 300 Norma and I’ve been trying to get close to his ballistics with the short 7, keep in mind “close” is relative here. Was thinking if I do go the AI AT route I’d do a 28” barrel that Tubb can spin up for me, and try to eek out a little more FPS, I suppose I could even do 30” but not sure where the point of diminishing returns might be with the short cartridge.
Yes, no legs rocked that AXMC in some really tough conditions, that was impressive. He was also the RO at the Precision Hunter stage where my scope turret just turned with no clicks because the set screws had rattled loose riding around in the racks on washboard roads in side by sides, lol. That sucked. Zeroed that stage and it took me half the next one to get my zero figured out on the clock.
My 300 WM AXMC did not do as all no-leg’s Norma in the ELR match. I signed up last minute and didn’t have great dope confirmed out to the distances we were shooting. Was really frustrating because it was on for the long stuff , (1000 yds plus) but not the short stuff. So my goal this year is a 7 Saum with good , reliable dope and low ES/SD for the match. No matter how good the ballistics are you still have to call wind and make corrections. My buddy Caleb actually did pretty well with that considering he shot a 6 CM, lol. Good thing the far targets had hit indicators!
My 300 WM AXMC did not do as all no-leg’s Norma in the ELR match. I signed up last minute and didn’t have great dope confirmed out to the distances we were shooting. Was really frustrating because it was on for the long stuff , (1000 yds plus) but not the short stuff. So my goal this year is a 7 Saum with good , reliable dope and low ES/SD for the match. No matter how good the ballistics are you still have to call wind and make corrections. My buddy Caleb actually did pretty well with that considering he shot a 6 CM, lol. Good thing the far targets had hit indicators!
So basically if you want a cartridge under 3" OAL and want to shoot the 175gr+ bullets a short mag of some flavour is the only option.
I was under the impression the SAW could do the heavies at short action mag length, is that not the case? Seems like the creators certainly intended that to be possible.
One of the better options.
Another way to look at it is to work out how fast you want your bullets going and choosing a case that will handle it comfortably.
This way you will not need to worry about things like having a slower barrel or being limited to certain powders or bullets.
Trying to get every last drop of performance out of a SA, standard bolt face, magazine limited COAL combination is interesting in theory
but becomes a lot easier if you discard one of those restrictions.
This has been my experience, I only went to 175s and they were still tucked deep into the case. I stick to the 160s. A 160gr projectile at 2.95-8" OAL has plenty of space for powder. If there was a suitable 150gr projectile the SAW would be running bloody quick.
ETA: I am curious to see what the staball could do with the 175s though.
Scott’s Colorado hunter match is now the championship match for the NRL hunter series. So the only way to shoot it will be to qualify for the championship. Having said that, I think a 7 saum would do very well in that series. I’ll be running my 6.5 saum.
I run a 28” saum.
With ADG brass and SA mag length 180’s I ran out of room with H1000 before I hit pressure(2850ish with 180 ELD @2.95) but it did shoot fantastic and was super consistent.
Loaded longer 2950 was easy with H1000.
With R26 I could get 2950+ with 180 Berger’s at mag length and if your realistic on pressure R26 temp stability is pretty decent.
I used the data on the hodgdon website. My final load was just over max. (.2 grains). I'm running small rifle primer brass. My barrel is a touch over 26".
Thanks noob, that stinks as I don’t compete so would not qualify, just do it for fun. Maybe try to make the NF ELR match if it’s in Casper, WY again.
Whats the big deal about StaBall, I get the temp stability and ball powder metering well, is it just a nice middle ground between H4350 and RL26 that just happens to work well in 7mm08ish cartridges, or is there something im missing?
If it's just another option similar to H4350, RL16, RL26 that still isn't available then I don't see whats ground breaking about it.
I'm running Norma brass, but thought ADG had a bit more room, maybe I got it in reverse. I'm right at 2.95 as well...
PV had it in stock last night so bought 8# jug, bought a bunch of H4350 as well, stuff has been rare so jumped on it while I had the chance. Will take me a while before I get to LD, but at least I have some now to play with. Would like to know what the secret sauce is with this powder, maybe being ball powder just gives more speed without filling up the case like short cut powders do...
It gives very good velocities in the 7-08. The 7-08 is one of those in between cartridges where neither the 4350's or varget give good velocity with the 162 class bullets.
Looks like similar burn rate too Superfromance so midway between H4350 and RL26.
I see my local actually has Staball in stock, unlike anything else.
Just need some bloody projectiles and could test it vs RL26, H4350 and Superfromance in my 6.5CM.
Do you remember how many grains of H1000 you were using for that 2850 load in your Saum?
I'm assuming IMR 7977 which is right next to H1000 on the burn rate chart
I have a 7 SAUM in a bighorn action that I love, now that AI is going to be introducing 223 and magnum bolt faces for the AT platform I think I may just need to pursue that as well. Question is, these will be in such high demand I think it will be a long time before us mere mortals get a chance to get our hands on them.
I think the AT-X will be in hands soon, MHSA had 150 of them already. The bolt faces could be months or years out knowing AI. And then like you said, may be hard to find in stock, etc.
I will say, if they get a working 223 AND magnum short action going, an AT-X would be the easiest system out there to swap barrels on. Would be sweet to run a practice 223 barrel on, then switch with an Allen wrench to your 6 or 6.5mm comp caliber, then shoot ELR with a SAUM or PRC the next weekend.
I will say, if they get a working 223 AND magnum short action going, an AT-X would be the easiest system out there to swap barrels on. Would be sweet to run a practice 223 barrel on, then switch with an Allen wrench to your 6 or 6.5mm comp caliber, then shoot ELR with a SAUM or PRC the next weekend.
I've never felt like I needed a switch barrel rifle but the AI system looks so easy (no need for nogo guage or torque wrench) that I could see myself actually utilizing the system.
If there were a chassis/stock that made the bare rifle weigh less than the ATs 12lbs I'd consider only having the one rifle.
I’ve gone back and forth on the switch barrel thing. I’m not going to rush out and buy another AT because I just didn’t use the quick change as much as I thought. The biggest advantage is that it’s actually a field expedient way to swap barrels/calibers with just a torque or even Allen wrench. AI nailed it there. With swappable bolts it gets more interesting but it’s still a pain going from a practice barrel to a comp barrel on the same system, quick change or no. The zeroing is the big thing.
For now my two bighorn origins with interchangeable bolt heads and barrels accomplish that better. One is in my backup chassis with 223 AI barrel for practice and the other is my dedicated match gun. It’s always zeroed and I am more confident in it this way. My second chassis is an XLR magnesium and I have a PROOF CF shouldered pre-fit 6.5 CM barrel I can throw on to hunt with or for a handy field rifle under 12 lbs with optic. Advantage of the Zermatt is that the bolt heads are $125 vs $500+ that I imagine the AI will be.
I’d be curious what the weight of the AT-X will be with a carbon fiber pre-fit though...
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