Bartlein Barrels Update

#551
ruger35 said:
No, just my first experience running almost all Bartlein's to have one 100+fps slower than others. I wasn't sure if it could be something material related, but my 6GT Modbb is faster than expected. Was just a simple question as I don't have much experience with Modbb.
Click to expand...
The material has nothing to do with it. All of the ammunition test barrels we've done with the BB material there hasn't been one question or concern over velocities or accuracy etc...

Actual bore and groove size of the barrel and chamber reamer specs are just one variable. If your previous barrel even if it wasn't a Bartlein had a tighter bore/groove or different spec reamer was tighter... that will drive up pressures which in turn normally bumps velocities. Not all the time but most of the time.

What reamer spec was supposedly used in your barrel? Post a chamber reamer print if you can?

How many chambers has that reamer cut?

Even in the same lot of powder... the powder can have a +/-3% variation in performance.

Bullets vary from lot to lot.

Those three things.... barrel, bullets and powder all have to work together more than anything else.

Later, Frank
Bartlein Barrels
 
  • Like
Reactions: Defender3, Baron23, DeathBeforeDismount and 6 others
#552
That would also be like saying... CM barrels are faster than SS barrels! That's a bunch of BS as well!

The barrel is nothing more than a pressure vessel guys. It's all about dimensions and tolerances.

What do you think is going to happen if you get a lot of bullets that is say +.001" oversize vs a different lot that is only +.0001" over min spec.? Same powder... same case, same primer etc... and typically it will bump pressures and bump velocities.

About 14 years ago... we made some barrels for R&D for the Navy. Caliber was 300WM. They bought barrels from several different places. Our barrels accuracy wise out shot everybody else but they went with a different brand solely because they got more velocity out of the other brand but the other brand is noted for making a tight bore barrel. And they wanted more velocity. I called the Navy up about it and said... nobody asked if we had different bore size options available. Unless you tell me otherwise I'm going to make you min spec. + the tolerance and I'm not going to make you tight bore / undersize barrel. That leads to other issues and pressure is just one of them.
 
  • Like
Reactions: Earnhardt, TiroFijo, Baron23 and 9 others
#554
DOD contracts... Do they ever make sense? Wanna see a swingset the Army would build?
 

Attachments

  • 20230922_060301.jpg
    20230922_060301.jpg
    145.7 KB · Views: 97
  • Haha
  • Like
  • Wow
Reactions: Belvedere, Chipster697, notacos4u and 3 others
#556
oldrifleman said:
Did the RFP list Velocity as a Critical decision criteria? Does seem to be a weird way to get velocity.
Click to expand...
Nope...

All I got was a email and a phone call for a quote for 2pcs. All I got was 30cal, 5R and 9 twist.

Nothing was ever mentioned about a spec for bore or groove size or was I ever asked if we can do anything differently.
 
Last edited:
  • Like
Reactions: Dolomite
#557
Frank Green said:
The material has nothing to do with it. All of the ammunition test barrels we've done with the BB material there hasn't been one question or concern over velocities or accuracy etc...

Actual bore and groove size of the barrel and chamber reamer specs are just one variable. If your previous barrel even if it wasn't a Bartlein had a tighter bore/groove or different spec reamer was tighter... that will drive up pressures which in turn normally bumps velocities. Not all the time but most of the time.

What reamer spec was supposedly used in your barrel? Post a chamber reamer print if you can?

How many chambers has that reamer cut?

Even in the same lot of powder... the powder can have a +/-3% variation in performance.

Bullets vary from lot to lot.

Those three things.... barrel, bullets and powder all have to work together more than anything else.

Later, Frank
Bartlein Barrels
Click to expand...
I will compare and see if the reamer is printed on the barrel. We compared 3 Bartlein barrels, 2 by one smith (prefit, one modbb and one normal SS 5R), and one by another (prefit SS 5R). It was all from the same group of handloads on the same day, 2 of the barrels were similar and the one modbb was slower. That barrel has been consistently slower, but accuracy is spot on so no complaints. Our initial thoughts were what you alluded to in your other post about differences in reamer/chambering.

I was genuinely asking out of curiosity and not looking to place blame, just trying to educate myself. We have noticed the powder velocity variance with humidity/temperature. Thanks for the reply and information Frank.
 
  • Like
Reactions: Baron23 and Frank Green
#558
ruger35 said:
I will compare and see if the reamer is printed on the barrel. We compared 3 Bartlein barrels, 2 by one smith (prefit, one modbb and one normal SS 5R), and one by another (prefit SS 5R). It was all from the same group of handloads on the same day, 2 of the barrels were similar and the one modbb was slower. That barrel has been consistently slower, but accuracy is spot on so no complaints. Our initial thoughts were what you alluded to in your other post about differences in reamer/chambering.

I was genuinely asking out of curiosity and not looking to place blame, just trying to educate myself. We have noticed the powder velocity variance with humidity/temperature. Thanks for the reply and information Frank.
Click to expand...
I didn’t take no offense at all.

If the BB barrel has a different spec reamer…. That can do it.

What’s the difference in velocity between the slow one and a fast one?

How many rounds on them?
 
  • Like
Reactions: Dolomite
#559
It
Frank Green said:
I didn’t take no offense at all.

If the BB barrel has a different spec reamer…. That can do it.

What’s the difference in velocity between the slow one and a fast one?

How many rounds on them?
Click to expand...
It could be a different reamer, it was bought at a different time.

They are ~100fps different, SS barrel has 900 rounds, modbb ~200 rounds.

Both are using the same brand action just for reference.
 
  • Like
Reactions: Dolomite
#560
Frank Green said:
Nope...

All I got was a email and a phone call for a quote for 2pcs. All I got was 30cal, 5R and 9 twist.

Nothing was ever mentioned about a spec for bore or groove size or was I ever asked if we can do anything differently.
Click to expand...
That definitely sounds like some shady shit. Even though the contracts are supposed to be set up to be almost cheat proof, they cheat in them all the time. I see some stupid shit sometimes; it makes me mad.
 
  • Like
  • Haha
Reactions: DeathBeforeDismount and Frank Green
#561
ruger35 said:
It

It could be a different reamer, it was bought at a different time.

They are ~100fps different, SS barrel has 900 rounds, modbb ~200 rounds.

Both are using the same brand action just for reference.
Click to expand...
I tell guys up to a 100fps that is normal from barrel to barrel variance. That's just the difference between them. Now if you would've told me say 250fps difference that is out of what I call normal.

Also keep in mind it only has 200 rounds on it vs the other at 900. How you are cleaning and how often in between the number of rounds fired.... and or type of powder being used... the fouling/carbon build up is different right now. With 200 rounds on it... any change in velocity or if you will the barrel settling down should be down.

If pounding nice small groups.... put an extra click on for elevation.

Any questions let me know.

Also I sent you a PM.
 
  • Like
Reactions: DIBBS, ruger35 and lash
#562
Basic user said:
That definitely sounds like some shady shit. Even though the contracts are supposed to be set up to be almost cheat proof, they cheat in them all the time. I see some stupid shit sometimes; it makes me mad.
Click to expand...
It’s done in non-mil industry all the time. A spec is often written largely by the preferred vendor and rubber stamped by the customer. But not provided to the remaining vendor base unless insisted upon. Then they’ll find out that the spec is written around a specific product.

Very common.
 
  • Sad
Reactions: carbonbased
#563
Basic user said:
That definitely sounds like some shady shit. Even though the contracts are supposed to be set up to be almost cheat proof, they cheat in them all the time. I see some stupid shit sometimes; it makes me mad.
Click to expand...
Hahahaha

Contracts set up to be fair? 90% of the time they have decided on a winner before the solicitation goes out. Specs and performance are designed to point to a particular product. I used to do it all the time with contracts, grants and cooperative agreements. Instead of letting the SME buy what they know will work...we have to go through the whole song and dance which ends up costing the gov program office way more in the long run not to mention wasted time.
Ok cool we save $100 per unit overall but just spent $30k in labor and travel to do the compeition... for a $5000 purchase. So those $400 barrels instead of $500 now cost you $3400 a pop. And guess who pays?

Atleast the micropurchase agreement is up to 10k now making these kinds of purchases much easier.

Anything left up to interpretation is a risk. A good procurement specialist solves these problems from the start.
 
  • Like
Reactions: Frank Green, lash and oldrifleman
#564
DeathBeforeDismount said:
Hahahaha

Contracts set up to be fair? 90% of the time they have decided on a winner before the solicitation goes out. Specs and performance are designed to point to a particular product. I used to do it all the time with contracts, grants and cooperative agreements. Instead of letting the SME buy what they know will work...we have to go through the whole song and dance which ends up costing the gov program office way more in the long run not to mention wasted time.
Ok cool we save $100 per unit overall but just spent $30k in labor and travel to do the compeition... for a $5000 purchase. So those $400 barrels instead of $500 now cost you $3400 a pop. And guess who pays?

Atleast the micropurchase agreement is up to 10k now making these kinds of purchases much easier.

Anything left up to interpretation is a risk. A good procurement specialist solves these problems from the start.
Click to expand...
Yep...

And it cracks me up when I have a inkling that something is off... and I ask questions and most of the time I get the deer in the headlight look on the phone. I can see it. Either they really don't know... or don't want to say anything.

I can't tell you how many times someone called to order ammunition test barrels for 300 and 338cal for ASR testing but didn't know that the rifling twist and profiles and chambers are specific to ASR and totally different than from Saami/CIP spec. I ask the question...is this for ASR or do you want Saami spec.? I get why? Because they're different. The reply is oh! I didn't know that.
 
  • Like
Reactions: carbonbased, Basic user and lash
You must log in or register to reply here.

Similar threads

W
MullerWorks Barrels Update
Replies
20
Views
1K
Cody S
Cody S
M
Short barrel 6.5 prc
Replies
47
Views
1K
XTREM HTR16
XTREM HTR16
KodaiSusumu
M24 clone-ish stock & barrel fitting - pst011 vs pst024
Replies
17
Views
449
KodaiSusumu
KodaiSusumu
HKSniper11B
Accuracy International - Alternative Barrel Clamp Torque Specs?
Replies
39
Views
757
BurtG
BurtG
U
Big Horn Origin barrel
Replies
13
Views
876
Bakerman87
Bakerman87
Top Bottom
Back
Home
Forums
Merch
Alerts