Bartlein Barrels Update

Frank Green · Oct 7, 2024

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.

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

Frank Green · Oct 7, 2024

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.

Frank Green · Oct 7, 2024

Oh... the velocity difference in the above example was like only 50fps... but they were all hung up on getting as much velocity as they could. Sorry but that's thinking backwards!

Basic user · Oct 7, 2024

DOD contracts... Do they ever make sense? Wanna see a swingset the Army would build?

oldrifleman · Oct 7, 2024

Frank Green said:
Oh... the velocity difference in the above example was like only 50fps... but they were all hung up on getting as much velocity as they could. Sorry but that's thinking backwards!

Did the RFP list Velocity as a Critical decision criteria? Does seem to be a weird way to get velocity.

Frank Green · Oct 7, 2024

oldrifleman said:
Did the RFP list Velocity as a Critical decision criteria? Does seem to be a weird way to get velocity.

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.

ruger35 · Oct 7, 2024

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

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.

Frank Green · Oct 7, 2024

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.

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?

ruger35 · Oct 7, 2024

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?

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.

Basic user · Oct 8, 2024

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.

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.

Frank Green · Oct 8, 2024

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.

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.

lash · Oct 8, 2024

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.

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.

DeathBeforeDismount · Oct 8, 2024

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.

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.

Frank Green · Oct 8, 2024

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.

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.

lange92 · Oct 15, 2024

First Bartlein did a 300 prc build custom chambered. MTU 28” finished. Excellent barrel couldn’t be more pleased. Will def try for more in the future.

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