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TP9SFX Plunk test

Posted: Thu Mar 28, 2019 9:00 pm
by Rubicon05
Who has done the plunk test on a SFX. Just got my new SFX with Viper today, wanted to do the plunk test for some reload OAL data and was surprised with the numbers, it is actual shorter than my CZ,

125 HAP plunked at 1.070

124 Berrys HBFPTH plunk at 1.075

Any body else have similar results?

Re: TP9SFX Plunk test

Posted: Thu Mar 28, 2019 9:43 pm
by GlennSFX
Personally I've tested up to 1.135. I believe @Weapon has successfully test 1.145.

Re: TP9SFX Plunk test

Posted: Mon Apr 01, 2019 7:39 am
by Weapon
That’s odd - my 135gr load was fine at 1.150” and I will have to go back and check my notes but at least one bullet was fine at 1.160”.

Re: TP9SFX Plunk test

Posted: Wed Apr 10, 2019 5:24 pm
by Texas1911
It all depends on bullet profile.

I'm sending my SFx barrel out to be throated. It should stop the leading problem I've got and will also allow me to seat those .357 sized bullets out to a normal length.

Re: TP9SFX Plunk test

Posted: Wed Apr 10, 2019 8:26 pm
by GlennSFX
I'll be testing a new round using the ACME 145 RN bullets. COL is specified at 1.15" and will do a chamber check.

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Re: TP9SFX Plunk test

Posted: Fri Apr 12, 2019 12:04 am
by BentAero
As Tejas mentioned, it's totally, totally, dependant on bullet grain and profile. Acme 147 RNFP will plunk easily at 1.160, as they are very arrow shaped, but that length is getting iffy with consistent feeding inside the magazine; any longer than that they bind up. 1.150" is rock steady.
Gallant 147's will only plunk under 1.015" as they have much 'broader shoulders', more blunt shaped then the Acme.
Bayou 145 RN tolerate a max of 1.035

Different guns will, or will not like certain bullets at certain power factors; there's no logic to it. My pal Darrell has a 20 yd indoor range at his house where he does chrono and accuracy testing. His Baretta production gun loves Barry's 147, but they're all over the map spread-wise in his CZ-01.They chrono nearly identical in the two guns.

In my SFx I powder for 130PF. Acme 147 and Bayou 145 work fine. Gallant 147 will have 'flyers' with Sport Pistol at 130pf. I may try titegroup in an attempt to get them to behave.

I bought a 250 rnd test box of Acme 135RN last year, and they are quickly becoming my favorite in the SFx. I've tried a mag or two during practical shooting on two occasions and found I can get the second shot off much quicker with the 135's, double-tapping alpha's noticeably quicker than my norm. 3.5 gr SP @ 1.140" makes 130-132 pf. That was enough for first overall in our local weekly IDPA-style fun shoot tonight. Going to have to place another order for those...
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