DON'T TRY THIS: Pushing 6GT to the MAX (Alpha Munitions, Bat Machine)

[@glockparaastra]

Love these in depth technical dives! Greetings from South Africa!

[@Ultimatereloader]

Thank you! Glad you are enjoying the videos!

[@HowManyLegsItHas]

Really found this and the 308 video very practical and interesting. Thanks Gavin!

[@chrisburckhard9122]

Love the 6GT content! Ive been going back and forth on getting a replacement barrel in 6GT. So, I'm trying to absord as much info as possible!

[@Ultimatereloader]

Glad it’s helpful!

[@wreckervilla]

It may not be the most glamorous of pressure testing but I'd like to see some pistol cases pushed to their limit, like how much of a difference is +P really?

[@barrymccockiner6641]

Or +P+, +P++, +P+++?

[@kennygates1756]

Where does he get all those wonderful toys....Bruce Wayne of the shooting world!

[@LoganSmith-hz6gr]

Ultimate reloader try your 280 ai next vs 7 rem mag with vv n560

[@harrypeterson9287]

I can see Bruce casually saying. "Well, it appears we found our max load, maybe dial it back half a grain." With the bolt firmly lodged in his eye socket and missing a few fingers.

[@aidendelong5869]

What a surprise to see this come up next!!! It was one I have really wanted to see and as always thank you!

[@gainforlife5877]

These shows are really interesting. What i´d like to see is the same thing done with a really old bottle neck cartridge. Like for instance the old 6.5x55 Swede that originates in 1894. That would be really interesting to see, what first up can be had out of such an old cartridge and second how it behaves when pushed.

[@seanf818]

Nice to see you guys are actually using pressure transducer instead of guestiments from Q/L

[@scaler1179]

I just acquired a rifle in 6mm xc. Bat Machine action and Nightforce scope. I love the 6mm chamberings.

[@rosspresta6571]

Gordon's Reloading Tool has 6mm GT and the pressures are close to your Measured presssure How is your correction factor determined ? Great job BTW. Very Interesting

[@maquereautin]

The recoil has got to be crazy. I was shooting 34gr of varget with 109s. Had heavy bolt lift every so often. Backed down to 32.8gr. Less recoil, still groups nice. That high of pressure, there's got to be ejector swipe. Little brass shavings getting down in there and stopping your action from working right.

[@mackellyman5642]

Worthwhile discussion with real-world tests...Hammerhead action, alpha brass, and 6gt chambering. Excellent content.

[@JohnnyTurbo87]

Pressure test on a brand new barrel over the span of 200 rounds to see where a barrel settles or breaks in

[@ewathoughts8476]

Trying to follow along, but hitting several data point problems. Is the Alpha case capacity shown in fired (unresized) or new cases? Quickload does have a 6 GT cartridge listing, but the case volume is in the 46.2 grain level. In order to use a simulation properly the user has to verify all component data like bullet length, case volume, boattail dimensions, case length after fired, etc., and not just accept the defaults from the simulation data files. At the overall length for cartridge (2.530") and barrel (24") in Hodgdon listing, and default 107 bullet length, the pressure simulated is 64565 psi and velocity 2924 fps at the 34.0 grains of Varget listed. So a bit higher pressure than Hodgdon declares and about 100 fps less velocity. If the case volume shown is new brass, then the fired volume is likely to be about 1.0 to 1.2 grains of H2O more. That would bring the simulation pressure down to 61306 and velocity down to 2895 fps. Adding the 4" of extra barrel the simulation indicates 3011 fps, and 2986 fps respectively. That would nearly equal the real velocity seen (2903 fps). Assuming the real case capacity is 43.3 grains of H2O we could then estimate that Quickload (QL) is overestimating the pressures by about 4% while estimating velocities very accurately at this one propellant charge. Now comparing the Hodgdon start data in the same manner we find the 30.6 grain charge simulates at 45815 psi and 2645 fps velocity. Somewhat lower pressure that the Hodgdon data suggest 48200 psi and 2679 fps velocity, about a 5% difference in the pressure and in the reverse direction. Since the start charge was not tested we have lost basic validation to the Hodgdon data. Secondly since your test showed 2903 fps with a longer barrel we have an additional problem in validation and calibration of your pressure reading estimates. Additional errors is projectile weight and length both projectile and cartridge OAL. So the big question is why your rig develops less velocity with a longer barrel than Hodgdon's barrel? Substituting the Berger 105 Hybrid at the same COAL as the Sierra 107 would result is a pressure decrease of 900 psi and velocity increase of 18 fps approx.

[@WaterZer0]

Please get them to make some 5.56 cases, so you can do a video on those!

[@donaldpowers8331]

The "rabbit hole" just got deepend. Very interesting.

[@bobkat1663]

Question - What was the barrel length? Great Show.

[@лопух-ф5я]

grt has a 6gt case and i simulate those loads and it was pretty close to the speeds and pressures that you measured

[@duggydo]

Gavin, you sure have come a long way from shooting a swimming pool. I am thoroughly impressed by you young man! 👍🏻👍🏻

[@esw2348]

Would like to see several common loads, as published in reloading manuals …. cartridge/bullet/powder/charge combinations tested to see how they compare to measured data.

[@waynemayle865]

Ok now do the same test with the 6mm creedmoor same barrel length powder bullets brass

[@JamesJohnson-if8rz]

I appreciate you and your channel. everything you do. however, let me be the first to say... fornicate that 6gt. why? what did it do the 6br and offshoots do? or... 6xc... or 6x47... or 6creed. which.. don't get me started on the creedmoor/hornady and the "marketing". Regardless, walk it back with the same barrel length; run 6creed. Purely speculatory. However, the notion of brass endurance and the display of documentation are all commendable.

[@Berube1984]

Just curious why quickload over GRT ?

[@adeniranm7647]

You need to do a brass comparison video. You can't just say, "Alpha brass isn't like originally brass." What does that even mean? How does it compare to Lapua (for example)?

[@alphamunitions5607]

Our OCD brass is much stronger than any other brass in the market If they did a brass test at these pressures they would have catastrophic failure. We have done these tests in house. Bruce mentions what happened to 6.5 PRC brass in the Video at lower pressures.

[@chuckkuang91]

O cool I’m gonna try this load at my next prs match XD

[@mannybarroga1878]

What do you think of 47 grains of varget pushing 175 smk to 2770 fps in 308 win. Lapua small primer is used.

[@charlesmullins3238]

My exact load for fn spr and dd5v3..h4350..superformance..n540. And few more all in that 47gr area

[@charlesmullins3238]

Correction..not fn spr..1:12 don’t like 75s as good as 68s..

[@noahburleson6112]

Awesome work! Would be super cool to see this same test with the 7PRCW n555 and 180 hybrids!!

[@Patrick-xd8jv]

It’s already been done

[@noahburleson6112]

@@Patrick-xd8jv Lol yes I know it’s been done and it has been accused of being flawed by a top f class action manufacture whom I will not name who thinks the PRCW is at 78,000psi pressure at 2900fps with that powder/bullet combo which is why it’d be nice to see another test done to confirm the testing they did is accurate.

[@kirkchapman80]

Push 7 rem mag but 190 grn bullets

[@AccuSol-ERN]

So.....for the extra 20k in pressure you got another 200fps? This is so negligible in PRS comp.........can't think of a time when I was shooting 6BR and missed but would have hit with a 6creed. Just sayin'.........good info though.......nice to know the margin of safety the brass can take.

[@Dragonfiregum]

The real kicker is anything this is compared to can also be pushed over pressure... so its kind of pointless. Just because you can push a 7.62x39 to 2750fps with 123gr doesn't mean you should regularly for example. Although that velocity gain brings that into a new realm when comparing it to other things. Just get the cartridge that can accommodate your needs without going crazy.

[@sethperry1323]

6gt can sling a 55gr bullet faster than 22-250 🎉

[@DougJohnson-g5f]

N 550

[@uralbob1]

As a handloader of 32 years, I’m not sure this is a good video to throw out there to our less studied and less experienced handloaders (including me)! Love your channel though!

[@839photo]

@DougJohnson-g5f VV does very well in my 6GT