BCM barrel accuracy.

[Eurodriver]

I disagree that M193 cannot be used as a measuring block. These rifles are not precision guns and their inherent accuracy should be measured using the ammo they are going to be shot with.

I have got no personal dog in this fight. My motives are simply wanting a rifle that shoots well.

[R0CKETMAN]

- agree with stick that RDO isn’t the right optic for accuracy testing. 50-100yd

- Could XM193 not be used for “basic” accuracy testing with magnified optic and all other variables being equal in the upper, sans bbl, comparing one to the other?

- What’s BCMs bbl source? Has it changed would be my first question.

Got two 11.5 BCM uppers. One ELWF the other gov/standard profile. Can’t speak to inherent accuracy as both have RDO’s.

[themonk]

Typically with any upper I get new or build if it's going to have an RDS on I will put a few hundred rounds for testing and then throw a 4-12x on it to see what ammo it likes at 100 yards. That primarily is with ammo that I would use for HD and typically from 50gr to 77gr. I don't really care how it shoots wolf Gold (my primary training ammo) I care how it shoots HD loads.

[Eurodriver]

- agree with stick that RDO isn’t the right optic for accuracy testing. 50-100yd

- Could XM193 not be used for “basic” accuracy testing with magnified optic and all other variables being equal in the upper, sans bbl, comparing one to the other?

- What’s BCMs bbl source? Has it changed would be my first question.

Got two 11.5 BCM uppers. One ELWF the other gov/standard profile. Can’t speak to inherent accuracy as both have RDO’s.

I 100% agree. A RDO is a terrible optic for accuracy testing.

However, I am not testing accuracy. I am comparing accuracy.

[DaBigBR]

I don't know about declining but I have long noticed less inherent accuracy from BCM than others. I built two SBRs for coworkers last year and both wanted the BCM name but a better barrel (and one wanted a 10.3" barrel). Both got what they wanted and are better for it.

I've got a pair of BCM rifles, one 14.5" CHF (or "BFH", as it were) and the other an 11.5" button rifled. Both put up about the accuracy you talk about (4 moa) and I accept that. Anything worse, though, and I might not be satisfied.

I have a couple 6920s and one of them will do a little over 1 MOA with 64 grain GDSP and a Strike Eagle. My BCMs do not even approach that.

[justin_247]

Thank you for making this thread, Eurodriver. This is a subject that warrants discussion.

[Tx_Aggie]

With M193, you are approaching or hitting the level of accuracy of the ammunition with those groups. That is nice shooting.

Thanks! I appreciate you saying that. Nice triggers and shooting slow fire, prone, supported off of a bag or pack helps quite a bit.

I have a fair amount of Prvi Partisan white box M193 purchased a few years back and both rifles seem to like it, but I also may have lucked into a good lot.

[markm]

I'd be interested in shooting a barrel that seemed sub par. With our target 77 gr load, we expect to see around MOA/no more than 1.5 MOA with any AR barrel.

[Eurodriver]

Deleted

[ssc]

Great topic. I am a fan of BCM. However, I have noticed that my multiple BCM uppers do not shoot as well as my Sionic's Uppers. As far as RDS, I sight in at 50 yards and they are all good to go. Those uppers with RDS are for up close and I have not done "accuracy" testing with RDS. My BCM uppers, with optics generally give my 4MOA with 193, my reloads and WG. I will say that WG is inconsistent. One lot may be 6 inches and another 4 inches. When I started shooting rifle matches, I noticed I would occasionally miss a shot at steel (Shooting BCM)and decided to bench test my BCM vs Sionics URG.

Same ammo, same shooters, same optic, same day. Results: Sionics 2 MOA, BCM 4 MOA. Notice, I said shooters. I had a few friends also do testing. The BCM had both BFH ELW and standard ELW. The sionics had the lightweight barrel. Hence, I had a purpose built Sionics URG done by Sionics and it is 1.5-2 MOA. 2 days ago, I had it out and placed clay pigeons on berms at 120 yards and 230 yards. Threw it over a bag on the bench using a razor 1-6 and though I missed a few, the pigeons went down 5 out of 6 times. The miss was usually the shooters fault. This is my rifle that will be used for competition. Never tested my 6920 for accuracy as it wears a RDS. I do have a noveske built by Wes Grant that is a true sub MOA rifle.

Edited to add that the accuracy testing, after checking my notes was done using a 1-4 scope, good weather, and using a shooting bag as a rest. I will retest using a sled and a 10X scope.

Cheers, Steve