Range results with a new POF SPR (gas piston AR-10 in .308 with 20" barrel).

[MCMXI]

Here are a couple of photos of my new POF SPR with a 20" barrel.

I have a POF in .223 and I like their gas piston ARs and have been planning on a .308 for a while. I wasn't sure what to expect in terms of accuracy or recoil and I was pleasantly surprised by both. This rifle has virtually zero recoil ... the muzzle brake and the buffer make this rifle suitable for anyone to shoot. This rifle has an ambidextrous slide release which I like and it appears to be typical POF quality throughout. I hastily made up 40 rounds yesterday using some crappy 12-year old FC brass and was able to send all of them downrange today without any drama. I didn't clean the barrel or any components between the 1st or the last shot. Here are some targets shot prone with a bipod at 100 yards. Once I get the load worked out (and some decent brass) I think this rifle will easily shoot under 1 MOA at 100 yards and maybe a lot further than that (kind of hoping for 600 yards). I was all set to break 1 MOA with the third group shown but messed up the last shot (or at least I think I did but it could be the load too).

When I got home, I removed the internals to see how much carbon had accumulated after 40 rounds. The gas plug, piston and op rod (half of its length anyway) had some fouling as expected. The bolt, carrier and firing pin were fairly clean though (shown before cleaning).

 

[C-grunt]

Nice rifle. looks like it shoots pretty darn good too.

 

[rbernie]

Very tasty - congrats.

Does this rifle use DPMS or Armalite pattern bits (magazines, etc.)?

 

[rangerruck]

excellent pics, really shows how well, it keeps crap from getting down into the bolt area/chamber face etc., which is so darn critical... thanks again.

 

[MCMXI]

Does this rifle use DPMS or Armalite pattern bits (magazines, etc.)?

It uses DPMS "bits" so it's compatible magazine wise with DPMS, KAC and C-Products.

Thanks for the positive responses. I did have an interesting experience with the rifle in terms of the POA and POI. I bore sighted the scope before leaving for the range yesterday and the first shot was 3" high and 3" left at 100 yards so not bad. The next shot was with the first, but after that, every shot for the next 13 rounds climbed about 1/2" to 1". I had to adjust my POA down twice (-6 MOA total). Eventually the rifle settled down and I was able to shoot the first group shown (shots #16 through #20). I didn't adjust the scope after that group. My first thought was that the scope mount was moving but I installed it with the recoil lug butted up (pushed forward) against the forward wall of a slot in the rail so it wasn't that. Now I'm wondering if the barrel was being polished with each shot and that was changing the POI. It looks like the barrel is chrome lined but based on POF's description I'm not sure yet. Here are the rifle specs ... any ideas?

Thanks.

 

[taliv]

yep, very nice!

 

[MCMXI]

taliv, thanks ... I'm going to swap the stock for a MAGPUL PRS. The VLTOR is perfect on my POF carbine but it's not ideally suited to the SPR. I want an adjustable cheek rest. I have a PRS on my "match" AR-15 but it's not compatible with the .308 due to the length of the charging handle. The 4lb Timney "match" trigger which POF calls T.I.T.S. is ok, but if I like the Geissele SSA that I'm trying out it, the Timney might go T.I.T.S. up. Other than that, no changes are planned. I'm looking forward to working up 168gr and 178gr loads for it over the next couple of months.

 

[taliv]

42.0 g of R-15 was my fav 168g SMK load

zak's got me shooting 155g lapua now though

 

[MCMXI]

I use a 168gr Nosler, Lapua cases and 43.2gr of Reloder 15 for my bolt rifle. That load produces 2,700fps of MV and is very accurate at 600 yards. However, I can see how a 155gr bullet with a BC of 0.508 would work very well (if not better). What MV are you getting out of your KAC SR-25? What's your barrel length?

 

[taliv]

really not pushing it at about 2760 fps, but also using VV N540, not R15 either with the scenars

 

[Lowlander91]

i have a friend who used to work there until he had to leave for college, and i believe the barrel is chrome lined.

 

[cat_IT_guy]

Very cool looking gun!

 

[taliv]

oh, about your POI stuff...

just because you have it pushed forward doesn't necessarily mean your larue mounts aren't moving. i had to tighten the screw on mine WAY past where the instructions said "most" people tension it to get it to stop. once i did, of course, it worked fine. before that, i was able to move it forward and back just a tiny tiny bit, though there was no side to side play

 

[MCMXI]

taliv, I remember the issue that you had with your LaRue mount. I suppose it's possible that the mount was moving backwards which would be equivalent to lowering the reticle right? Lowering the reticle moves the POI up if the POA is the same ... hmmm ... I'd better take a close look at the mount.

benatilstate & Lowlander91, thanks for the comment and the help.

 

[gvnwst]

Great looking rifle 1858! I would love to see how well it can do at longer ranges.

 

[MCMXI]

Great looking rifle 1858! I would love to see how well it can do at longer ranges.

Thanks and me too!! I'm going to continue to work up loads for it this coming weekend and hopefully will use it at the next 200, 300 and 600 yard match in a few weeks. It's a joy to shoot ... addictive actually.

 

[Lowlander91]

i talked to the friend who worked there today he said it isnt chrome its a much harder material better stuff. says you can dull a knife on it guess cant rember the name tho. if i ctalk to him again ill post the material.

 

[Lowlander91]

Ok it is called melanite i belive he said it is black and is harder than chrome so it prevents copper or anything to geting stuck in the barrel and messing with your accuracy. idk to much about this stuff as im a shotgun man he is my go to for AR info tho

 

[MCMXI]

Lowlander91, thanks very much for the information. I'll have to do some research on melanite.

I would love to see how well it can do at longer ranges.

I've been thinking about your comment and now I'm wondering what I should expect in the way of accuracy at 600 yards (assuming no wind). Anyone care to suggest a 20-shot group size that they would consider acceptable at that range?

taliv produced a 5-shot sub MOA group (maybe as small as 1/2 MOA IIRC) at 600 yards a few months ago, but then again, he's got one of those high end KAC SR-25s. This is a lowly POF with a 3.5-10x scope, so 2 MOA might be all I can hope for.

 

[gvnwst]

This is a lowly POF with a 3.5-10x scope, so 2 MOA might be all I can hope for.

LOWLY?! What about it is lowly?!?!

I would guess that with loads tailoried for the rifle, and in fair conditions, you can shoot around MOA. I have done sub MOA at 500 with my .223 POF, and some old match ammo. Those were 5 shot groups though, not 20 shots...

 

[MCMXI]

LOWLY?! What about it is lowly?!?!

Lowly in the sense that it's not a $7,000 rifle like the SR-25. I'm going to use 178gr A-MAX bullets (single load) at 600 yards so maybe it'll do ok.

I'm still not sure if I like the Modular Railed Receiver (MRR). It adds some height to the receiver. The adjustable cheek piece on the MAGPUL PRS stock will help with that though.

 

[kwelz]

Very nice weapon you have there.

Question. Any sign of carrier tilt or does this bolt design help alleviate the problem?

 

[MCMXI]

Very nice weapon you have there. Question. Any sign of carrier tilt or does this bolt design help alleviate the problem?

Thanks. I've only put 40 rounds through it so far so it's too early to tell. I have a POF in .223 which has had more rounds through it and there's no sign of carrier tilt with that one yet. I'll keep an eye on both and will report back if anything crops up. The POF rifles seem to be very well engineered with one of the simplest AR GP systems out there.

 

[taliv]

SR25s are nice, no doubt, and that piston will do nothing to help your accuracy, but i'd bet you can still pull off MOA pretty easy. DPMS doesn't have any problem making accurate rifles a lot cheaper than Knights.

The target you're talking about was 3.8" if I recall @ 600

I went out this weekend and didn't do so hot. a couple 9" 5-shot groups at 800 yrds, but i had a good bit more wind than i did when I shot that 600 yrd group.

 

[Winston_Smith]

Thanks for the range report and pictures. I have been thinking about one of these myself