Building up a service rifle

[colt_fan]

This will be my first AR to be built up as a service rifle, I have a few questions and am looking for some input and pointers.

Currently, I have a NOS Colt A2 upper without a barrel. I was planning on upgrading it to NM sights. The lower I will be using is from the group buy from RemSport. The LPK I have for it is the standard RRA, but was thinking about getting a 2 stage instead. Unfortunately I'm trying to understand the rules and regulations of what qualifies as a standard service rifle. So does putting a 2 stage trigger on it change the definition of the rifle so that it can not me used in service rifle competitions?

Can this barrel be used in the DCM Service Rifle competition?

The Remsport profile is .920 Dia. to the gas block and then .725 dia to the threads or end of the barrel. All these barrels including the M4 barrel will be in stainless steel only. They will all have timed barrel extensions and M4 feed ramps and be chambered for 223/556 with 1:9 twist.

The barrel is not set up for a pinned A2 front sight, so I was thinking of using the Bushmaster A2 front sight that uses a set screw. The barrel profile is 0.725 from the gas block forward. Also being in MA, the barrel will have a target crown on it.

Thanks in advance!

 

[M1911]

Currently, I have a NOS Colt A2 upper without a barrel. I was planning on upgrading it to NM sights. The lower I will be using is from the group buy from RemSport. The LPK I have for it is the standard RRA, but was thinking about getting a 2 stage instead. Unfortunately I'm trying to understand the rules and regulations of what qualifies as a standard service rifle. So does putting a 2 stage trigger on it change the definition of the rifle so that it can not me used in service rifle competitions?

You can use a 2-stage trigger in service rifle. But it must break at greater than 4.5 lbs.

 

[bpm990d]

If the barrel is going to finish at 20 inches you should be ok. The barrel is probably not the best twist rate, but it should be ok. What are you planning to shoot at 600 yards for bullets? You are probably maxed out at a 75 Hornady HPBT. I've shot them out of a 9 twist and they were GTG.

You can get a front sight base with four set screws from someone like White Oak. You can also take a regular base and tap it yourself. You can still use the four set screws on a barrel without flats milled into it. The set screws are only there to hold it while you zero the front sight for windage. Once it's zeroed you want to glue the front sight on with 290 wicking loctite. You can use other stuff like the 640 sleeve retainer but the wicking stuff works well.

You can also just tap the bottom of the bayonet lug (or where it use to be) and use a singe set screw and loctite. I personally think this is an easier set up to get the front sight zeroed but I used the 640 loctite since it's a little stronger and only had one set screw.

Good luck,

B

 

[M1911]

The barrel is probably not the best twist rate, but it should be ok.

Good point. Since you are building up from scratch, there really is no reason to go with a 1:9 twist. Get 1:8 -- better for heavier bullets on the 600 yard line.

 

[bpm990d]

If the chamber is really short, you can shoot Berger 70gr. VLDs and they would be competitive with the 80s. If the chamber is too long, the bullets bearing surface is so short, that it will fall out of the case before it gets close to the rifling. Most likely the Hornady 75s will be about it.

It is a better choice to go with a faster twist, but he could probably get a season or two out of the barrel without much heartache.

B

 

[colt_fan]

Good point. Since you are building up from scratch, there really is no reason to go with a 1:9 twist. Get 1:8 -- better for heavier bullets on the 600 yard line.

Hmmm, unfortunately I've already purchase the barrel. But I could always use it for something else down the line.

 

[M1911]

It is a better choice to go with a faster twist, but he could probably get a season or two out of the barrel without much heartache.

Agreed. But if he's building it up from scratch, rather than using an already-barreled upper, then there's no reason to compromise on a second-best barrel.

 

[M1911]

Hmmm, unfortunately I've already purchase the barrel. But I could always use it for something else down the line.

Well, you could use it within the limitations listed above, and if you get serious about service rifle competition rebarrel in a couple years.

 

[colt_fan]

How bout NM sights, is the BM the same as the Armalite in terms of quality? Do I really need a NM front sight?

 

[colt_fan]

It's not likely I will be shooting out to 600 yards anytime soon. Longest range that I have access to is a 300. So it's probably good enough for now...

 

[M1911]

How bout NM sights, is the BM the same as the Armalite?

Sorry, don't know.

Do I really need a NM front sight?

You definitely need a NM front sight post -- a regular front sight post is too thick. This is really noticeable at the 600 yard line where the apparent size of the bull will be smaller than your front sight post. I never went as far as bpm990d was suggesting for zeroing the front sight windage. But then I never went beyond sharpshooter in service rifle either, so don't think I'm some sort of service rifle expert. I'm more of a service rifle novice and that was 10 years ago.

You also need NM rear sights. They will have a smaller diameter peep, and the adjustments are finer.

 

[M1911]

It's not likely I will be shooting out to 600 yards anytime soon. Longest range that I have access to is a 300. So it's probably good enough for now...

That's not true. You have access to a 600 yard range.

You're in metrowest, which is just a short drive from Reading Rifle & Revolver. They have matches most every weekend and you don't have to be a member to shoot in a match. http://www.readinghighpower.com/high_power.htm

It really is worth it to shoot at 600 yards. You learn about wind and trajectory real fast. Reduced distances matches are fun, but they just aren't the same.

 

[Admin]

That's not true. You have access to a 600 yard range.

You're in metrowest, which is just a short drive from Reading Rifle & Revolver. They have matches most every weekend and you don't have to be a member to shoot in a match. http://www.readinghighpower.com/high_power.htm

It really is worth it to shoot at 600 yards. You learn about wind and trajectory real fast. Reduced distances matches are fun, but they just aren't the same.

Reading, MA and Nashua, NH are both great places to shoot a full distance national match course.

 

[M1911]

Reading, MA and Nashua, NH are both great places to shoot a full distance national match course.

Oh, yeah, forgot about Nashua. Golf Range at Ft. Devens was awesome as well, but last I heard it had been closed to civilians. Too bad, because I learned about wind and 55 gr bullets real fast on Golf Range.

 

[bpm990d]

How bout NM sights, is the BM the same as the Armalite in terms of quality? Do I really need a NM front sight?

I'd get either a White Oak, Northern Competition or a First Strike. There probably are some others that are ok, but if you are not getting them on a rifle, I'd step up and get a really good aftermarket one.

B

 

[colt_fan]

Damn, this is getting expensive quick! How bout a list of items that are priority.

Barrel
Sights
Trigger

 

[Admin]

Just get a complete upper made properly from John.

http://www.whiteoakarmament.com/complete_uppers.htm

 

[bpm990d]

Seriously, if you have the barrel already you should be fine unless you can get someone to take it off your hands for what you paid for it. For reduced courses a 9 twist is just fine. It will work for full distances as well. It's just not optimum.

Ask around for people dumping RRA triggers. A lot of people upgraded to Geiselle triggers and have a spare RRAs ones kicking around. You can probably get one for $50.

I think the Northern Competition sights are about $120.

B

 

[PatMcD]

Remember that you will need a Service Rifle float tube. Add $100-$150 for one.

 

[colt_fan]

Remember that you will need a Service Rifle float tube. Add $100-$150 for one.

Do I really need that? Or can that be something I get down the line in addition to a barrel with 1/8 twist.

 

[wahsben]

Do I really need that? Or can that be something I get down the line in addition to a barrel with 1/8 twist.

It looks like the White Oak Armament upper comes equipped with it.

 

[colt_fan]

It looks like the White Oak Armament upper comes equipped with it.

Yeah, but if I were to build it up myself do I need the float tube?

 

[PatMcD]

I'd say definitely. Doesn't matter how big that barrel is, sling pressure will move it. Without a float tube, it is impossible to get consistant pressure when in the sling from shot to shot.

You want an accurate upper. Without it, you will never improve because you have no idea if that last bad shot was you or the rifle.

 

[bpm990d]

Yeah, but if I were to build it up myself do I need the float tube?

Yes. I did shoot one for a season in 1990 without one. Best score I shot that year was a 469. Would I have shot better with one? Maybe, but probably not too much better.

If it's a question of shooting or not shooting, shoot it without one. You will still have fun and be able to shoot good scores (relatively speaking).

B

 

[M1911]

Yeah, but if I were to build it up myself do I need the float tube?

Building it yourself or buying it isn't going to change whether or not you need a float tube.

Either you need a very thick, strong barrel (like my Armalite, nee Eagle Arms, Golden Eagle), or you need a float tube. Otherwise the tension of a tight sling will change the impact point.

For your average profile barrel, you need a float tube.

 

[Dan S]

Building it yourself or buying it isn't going to change whether or not you need a float tube.

Either you need a very thick, strong barrel (like my Armalite, nee Eagle Arms, Golden Eagle), or you need a float tube. Otherwise the tension of a tight sling will change the impact point.

For your average profile barrel, you need a float tube.

Regardless of barrel profile, a float tube is needed to avoid deflection due to sling pressure. The barrel is only attached to a thin wall of aluminum, it doesn't take much pressure to move the point of impact.

 

[tdeon221]

You'll save money buying a completed upper from White Oak, First Strike, or Northern Competition and have a no comprimise upper you can shoot in any venue, reduced course or full distance XTC (which is what I strenuously recommend if you want to truly learn how to shoot a service gun). I've done what you're contemplating doing and it costs more parting it together yourself. With the Colt Upper and Lower your also in for some fun because of the big forward pin and sometimes big trigger pins. For front sight, shoot what you like. I shoot a .072" and I am not in the minority. It gives you something to look at and the option of being able to gauge a center hold on the bull if you choose. Rear apertures .038-.042" work for most in different light, and light is a big thing with a post front sight. Triggers are preference too, most shoot a two-stage. Jewell, Rock River(tuned by White Oak), Geisselle to name some preferred triggers. Or sell the Colt and go by a Bushmaster DCM gun complete and some "legal" 20 round mags and a Turner Leather Sling and start popping caps. You can make at least Master with that gun, all for under 1500.00 bucks. We won't even start on reloading for 600yards yet.

 

[Jasper]

While i do love White Oak, i ended up with a Compass Lake service rifle upper. 1:8 Douglas air-gaged barrel, NM sights, free floated and (coming soon) 1/4x1/4 sights. It'll outshoot me any day of the week.

i've been buying gear for highpower a little at a time (as money allows), and honestly, aside from handloading my own ammo, the Geiselle trigger has made the single biggest improvement in my shooting. (your results may vary). When my Creedmoor hardback coat comes in, i'll let ya know how much of a difference that makes

 

[tdeon221]

That's the way I bought in to highpower. I did hold out and buy the best I could, so it took a little longer to collect it all. Didn't want to spend the same money two or three times. That's what I'm afraid scares people away is the initial outlay for the minimum required equipment, and we need more shooters! A good coat showed the biggest single improvement in scores, like thirty points. Next most important to me was the spotting scope.

 

[tdeon221]

Forgot Compass Lake. They're one of the top builders too, great to do business with.