Adjusting a load for hollow base bullets...


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KBintheSLC
November 23, 2010, 02:42 PM
I recently decided to try a case of 124g 9mm Berry's HBFP bullets. Just wondering if I need to adjust my seating depth (oal) and powder charge to account for the larger case capacity and different bullet length... relative to standard flat base load data.

Thanks

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rcmodel
November 23, 2010, 04:18 PM
No.
If you were to be using full-tilt boogy jacketed bullet MAX loads, you would have to back off and work up to it again.

But since Berry plated bullets are only recommeded for mid-level or reduced jacketed bullet data, it will not change anything enough to matter.

What will change things is the truncated cone shape of those bullets.
You will have to seat them deep enough for the full diameter at the beginning of the ogive to miss the rifling lead.

That will almost always be a shorter COL then a RN bullet could be for instance.

Take the barrel out of your gun and use it as a guage at the loading press to determine what COL needs to be to miss the rifling.

rc

KBintheSLC
November 23, 2010, 04:44 PM
Good advice RC... I'll try using the barrel as a gauge. The loads are indeed pretty mild... my concern is that they do not become too mild as a result of the added capacity. I did notice how awkward these look when seated to the same OAL as a RN loading. I imagine the Glock factory barrel I am going to shoot them through will be more tolerant than some tighter match-grade chambers as far as feeding these things.

rcmodel
November 23, 2010, 04:48 PM
They have a longer bearing surface seated in the case than a flat base the same weight seated the same COL.

That would about cancel out the extra capacity caused by the hollow base.

rc

Walkalong
November 23, 2010, 04:59 PM
I have shot the Berrys 124 Gr HB (1.045 O.A.L.) and the Berrys 124 Gr HP (1.040 O.A.L.) bullets with the same loads using two different powders and velocity levels and the differences in the average velocities were 6 FPS & 15 FPS, with the HP having the edge both times.

KBintheSLC
November 24, 2010, 03:03 PM
Sounds like the difference is not significant enough to make a real difference. I think I will seat it a bit deeper than the same RN load just to make it feed better. So, do you guys think there is any real advantage to using HB bullets?

rfwobbly
November 24, 2010, 03:12 PM
I've loaded and shot all the Berry 124gr bullets. All Berry's FP bullets end up seating deeper because that nose style bullet brings the .355 diameter out much further than say their 124gr RN. So you do end up with a shorter OAL than any weight Berry RN.

I found that the HB void is not large enough to allow the bullet to expand to fit the bore, it's seems there merely to lengthen the bearing surface. Another nice thing was that it seems to hold about 0.2gr of powder, so if the short OAL is getting you near compressed load territory, then using these will add some insurance.

My testing showed they also shot better than the 124gr Berry HP, too.

No need to significantly adjust the powder for any Berry 124gr if you're doing target loads. I generally use 4.3gr of Win231.

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