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GeorgeB
10-11-14, 21:40
I'm new to this forum, and am learning so much, thank you! Can you please offer me advice on building a BCM SPR, that is, a precision 5.56. I'm thinking of a BCM upper with a 20" barrel, and putting a Geissele trigger group for precision rifle work. I'd appreciate any thoughts you have on the build of this rifle. Thank you.

If I posted this in the wrong place, my apologies.
Kain
10-11-14, 21:53
Might have better luck in the precision semi auto sub forum. You could ask a mod to move it.

Now that said, How far out are you wanting to be shooting? Budget? What is accuracy goal? MOA? Sub MOA?

I would argue that a standard barrel with ammo it likes, a good shooter, glass, and free floated would be capable of MOA. Perhaps not ideal, but possible. My 16 inch BFH middy before I installed my DD Omega rail printed near MOA groups at 100 yards with my behind an ACOG and a milspec trigger, and that was with 55gr Steel match on occassion. Now granted it is generally more of a 2MOA rifle with my ACOG and decent ammo, but I haven't been pushing it hard lately since I am have running my second BCM BFH upper with Larue rail more since I finsihed that build.

Now that said, unless you are married to the 20 inch barrel or wanting the extra speed to reach out 500+, and even then, I really think you would be fine with a 16 inch gun. I would also look at BCM's stainless barrels if you are wanting to try to get as much accuracy as possible out of their barrels. I believe, if you have the budget and don't mind quad rails, BCM still have a 16 stainless upper with a DD free float rail on sale for $700, that would include BCG and BCM brake as well.
SeriousStudent
10-11-14, 22:22
Kain is correct on the proper sub-forum, so I moved it.

And I'll go out on a limb and agree with him on the 16" stainless BCM upper. And I think it's a pretty sturdy limb, since I'm ordering one this week.
dramabeats
10-12-14, 02:03
Kain is correct on the proper sub-forum, so I moved it.

And I'll go out on a limb and agree with him on the 16" stainless BCM upper. And I think it's a pretty sturdy limb, since I'm ordering one this week.

Any merits to a 18" rifle length for 3 gun?
BrigandTwoFour
10-12-14, 09:07
Any merits to a 18" rifle length for 3 gun?

The rifle length gas will run just a hair smoother, and the extra two inches of barrel will give you a hair more velocity. It' more personal choice than anything.
Robb Jensen
10-12-14, 10:49
I just finished mine last week.

http://img.photobucket.com/albums/v408/gotm4/imagejpg1-12.jpg
SeriousStudent
10-12-14, 11:01
Any merits to a 18" rifle length for 3 gun?

I have honestly never thought about it. I enjoy watching 3gun competition, but have never participated. I don't have any plans to do so in the near future. Sorry that I could not provide a better answer.
Singlestack Wonder
10-12-14, 18:57
BCM offers a great 18" series of SPR uppers.
thecolter
10-12-14, 23:04
Not to take anything away from BCM, but I recently built an 18" SPR'ish rifle using a Rainier Arms Ultramatch (Shilen blank) SPR barrel mated to a MEGA Arms receiver set. It's been a solid, consistent .5 MOA rifle with just about all quality ammo I've put through it given I'm doing my part. It really likes 75 grain Hornady BTHPs with 24 grains of TAC.

Just offering another option that I'm really happy with.

https://farm6.staticflickr.com/5600/15522365442_c001a03af1_b.jpg

Here's a five shot group with 75gr Hornady BTHP's @ 100 yards.

https://farm4.staticflickr.com/3942/15335920229_676fffc5d8_b.jpg
Vegasshooter
10-14-14, 13:53
I have had wonderful success with my BCM SPR. I go into the build in my thread "New Personal Best". I can tell you that .70-.75 MOA is quite the norm with factory Federal GMM in both 69 and 77 grain. I can't tell a difference at 100 between the two. The 8 grains is not very much weight, but there is a difference at 500+ yds. I'm sure with hand loads and some tailoring, .4-.5 would be very doable. I know there are a ton of choices out there, but I personally think you would not regret the BCM.
Pappabear
10-14-14, 20:57
As previously stated, many folks start with the 20 inch gun in mind but find a 16 or 18 is fine. A 20 inch gun will give more velocity and the potential for a rifle gas system.
An 18 inch gun can get you a middy and a great middle ground. I built a White Oak that we shot the hell out of it. Heavy bull barrel 20 inch classic SPR. I switched the barrel out to a 16 inch bagara to try it out. We rung the steel at 1K this week with 77gr SMK's. Took Mark 17 mils of postage to get there, but it went "dink".

I would buy a BCM upper pre built and then choose a lower to your liking and roll.
Pappabear
10-14-14, 20:57
Not to take anything away from BCM, but I recently built an 18" SPR'ish rifle using a Rainier Arms Ultramatch (Shilen blank) SPR barrel mated to a MEGA Arms receiver set. It's been a solid, consistent .5 MOA rifle with just about all quality ammo I've put through it given I'm doing my part. It really likes 75 grain Hornady BTHPs with 24 grains of TAC.

Just offering another option that I'm really happy with.

https://farm6.staticflickr.com/5600/15522365442_c001a03af1_b.jpg

Here's a five shot group with 75gr Hornady BTHP's @ 100 yards.

https://farm4.staticflickr.com/3942/15335920229_676fffc5d8_b.jpg

Nice looking rig.