altho not  new to  the  AR world  I am  unfamiliar  with  the  SPR concept.    Is the SPR  a variant  in use  by  our military ?  What does an official  SPR look like ?  I have seen some pics of  "SPR's" here in the forum  but they  seem to vary   quite a bit  in form.   Also  many of these pics show  a  collar  type device on the  barrel between the  front sight and the  flash hider/muzzle break.  what is the purppose of the collar?  Thanx for the info.

Quoted: altho not  new to  the  AR world  I am  unfamiliar  with  the  SPR concept.    Is the SPR  a variant  in use  by  our military ?  What does an official  SPR look like ?  I have seen some pics of  "SPR's" here in the forum  but they  seem to vary   quite a bit  in form.   Also  many of these pics show  a  collar  type device on the  barrel between the  front sight and the  flash hider/muzzle break.  what is the purppose of the collar?  Thanx for the info.

The SPR is an AR-based rifle fielded in certain situations by the US Army, kind of like a NRA 'Space Gun' match weapon, but set up for military purposes (eg as a semi-auto sniper rifle)....

It has an 18" stainless steel free floated heavy barrel, rail system, a flat top upper, and a special muzzle break made by OPS Inc that is designed to accept a supressor made by the same company... They are allways equipped with some sort of optic, and generally have a Harris-type bipod. The gun is designed to be used with 77gr OTM ammunition (Mk262)...

The USMC has a similar-but-different concept they call SAM-R (kind of like the similar-but-different bolt-action sniper weapons (M-24 vs (whatever that gun is the USMC builds from a Remmy 700 action))...

Thanks for the  skinny  Dave_A    now  i feel  a bit more educated.    might be fun to  build one of those  too  

Good thread...very informative.  I love this site.  

My version of a Mod1 clone.  Dated pic, as I changed the buttstock lately.

Even more detailed information:

from MSTN forum in Industry Section

 i looked at the ops inc  brake and  it is  stainless and polished how  do  you arrive at the   dull black finish also  still   unsure  about  that collar piece on the barrel.  what is  the function of that  

Quoted:  i looked at the ops inc  brake and  it is  stainless and polished how  do  you arrive at the   dull black finish also  still   unsure  about  that collar piece on the barrel.  what is  the function of that

The Ops Inc supressor has internal threads that mate with the threads on the brake.  The collar in the back centers up the supressor with the bore and, when the supressor is tightened onto the brake, it also puts a small amount of tension on the last few inches of the barrel, which, reportedly, makes the upper slightly more accurate.

Pics of a custom Ops Inc type FH I own and how it is constructed:

ah  i see !!!!  again thanks for the  good info

Mongo,
That rifle looks great!

Would you recommend using a dedicated lower for an SPR?
I ask because I'd love to build a Mod1 style upper and be able to switch back & forth.

Would that work? or should it be treated as it's own thing...hence the S ?

Quoted: Mongo, That rifle looks great! Would you recommend using a dedicated lower for an SPR? I ask because I'd love to build a Mod1 style upper and be able to switch back & forth. Would that work? or should it be treated as it's own thing...hence the S ?

Mine has a dedicated lower with a JP trigger group.  It's really just a target rifle, but pretty accurate for 18".  I would say as long as you are swapping between dedicated long range uppers, one lower could serve for two or more uppers.  That's how I did it for the last ten years.  I had one pre-'94 lower with a bunch of "spare" uppers for that lower.

Thanks for the info!

I think the "smartest" route for me is to eventually build a dedicated long range set-up.
The trigger group alone is probably best suited for this.

back to the checkbook!

Quoted: back to the checkbook!

I find the credit card much easier to use.

SPR means Special Purpose Rifle like a sniper rifle it is a SPR the term has been used for a long time go Goggle SPR and you wil see some old rifles using SPR. It is like SPS Special Purpose Shotgun like Remington uses(11-87 SPS)My Bushmaster is called a SPRMINTER it is have SPR and have Varmit gun LOL