Hollow base vs Flat base

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wcjjr

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Another newbie question. All of the load data I see is for Berry's HBRN. Would the data be the same for flat base bullets?
 
Assuming the same weight and loaded to the same length or longer it should work fine. As usually best practice is to start low and work up when you make minor changes in a load like this. What specific bullet are you going to use. There may be data in other sources using that exact bullet.
 
Same weight ='s same data.
That might be making is a bit too simplistic. Assuming same bullet construction (lead, jacketed, copper) and similar shape, then yes. Using data for a lead bullet under a solid copper bullet could get you in trouble. Seating a long pointy round nose bullet to the same OAL as a wad-cutter or similarly very blunt profile bullet of the same weight could also potentially get you in trouble.
 
start low and work up

^this.

In many, many cases, “same weight = same data” is not true, so do not follow that mantra blindly. Different jacket thicknesses, different lead composition, varying lube grooves, different bearing surface lengths - and a handful of other parameters will influence how a bullet resists traveling down a bore. The hollow base cavity is an example - a load which fits under a hollow base might not fit under a longer nosed flat base bullet without significantly increasing pressure. As another example, I put charge weights under a 180grn Speer Spitzer in 357/44 mag which would might blow up a Redhawk if I put them under a 180 Hornady XTP, or even under a 158 XTP. The bearing surface of the spitzer is considerably shorter, so it slides down the barrel easier without as much “back pressure”. Similarly, an HBRN is typically longer than a flat based RN. The skirt gives up some resistance since it’s not supported, but the bearing surface IS longer. The berry’s HBRN’s I have used hardly fit what most think of when we picture HB bullets, as the “skirt” is exceptionally thick - so if I hazard a guess, I’d say FBRN data will be slightly higher charge weight than the HBRN - so using that data SHOULD be ok, but under-performing.

Flat based bullet data is easy to find. Keep looking, or ask here for a photo of a reloading manual page. Lead data is generally recommended for plated bullets, so you shouldn’t struggle to find what you need, flat based LRN data is everywhere.
 
Berry's HBRN is thick plated with hollow base and thick plated bullets (usually rated to 1500 fps) can be driven to full jacketed load data without decrease in accuracy.

If you want load data for solid base RN, you can reference Speer load data for TMJ RN (also thick plated) - https://www.speer-ammo.com/reloading/handgun

While thick plated bullets can be driven to jacketed load data, if you are using regular thickness plated bullets (usually rated to 1200-1300 fps), I found referencing lead load data to produce good results (accuracy).

Keep in mind that max velocity rating is for point of plating failure and not necessarily for accuracy. With regular plated bullets, I limit velocity to mid-range jacketed load data as using high-to-max jacketed load data with regular plated bullets tended to decrease accuracy.
 
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That might be making is a bit too simplistic. Assuming same bullet construction (lead, jacketed, copper) and similar shape, then yes. Using data for a lead bullet under a solid copper bullet could get you in trouble. Seating a long pointy round nose bullet to the same OAL as a wad-cutter or similarly very blunt profile bullet of the same weight could also potentially get you in trouble.


OOPS, MY BAD!!!!!

I had no idea the op was comparing berry's hbrn data to a long skinny sp bullet or the berry's rbrn bullet data to a 300gr wc. And here I thought the op was asking about using the berry's hbrn data to their same weight rn flat based bullet.
 
I had no idea of the size of the hollow base on these bullets

https://www.berrysmfg.com/product/bp-9mm-356-115gr-hbrn-tp
View attachment 904285

Anyone know why they did this?

I would be tempted to fill the cavity with a hard grease and see if that keeps the fouling down and the barrel cleaner.

how is this for a concept from the past?

View attachment 904286

Yes, extreme accuracy in a wider range of firearms/bbl.'s. The thick walls of this style hb can withstand high pressures and still function/expand/seal as any hb bullet would do.

I tested 3 or 4 different hb pin shapes using a lyman 35870 hb mold and ended up with this hb bullet to use in a nm 1911 chambered in 9mm for 50yd line loads.
yRoLzs2.jpg

Worked on the shape/design of this keith bullet using a lyman 429422 (hb version of the keith 429421 swc) looking for a hb swc that the hb performed best in the 18,000psi/19,000fps range.
rVx5uvQ.jpg

That hb pin made this bullet that was shot in a 2 1/2" bbl'd 44spl.
Swqedh0.jpg

After getting the correct hb shape/design it took a couple of tries to get the hp right. The end result was a hb hp swc for the snubnosed 44spl.
FTFbMo6.jpg

Most reloaders don't understand hb bullets & rely on too much urban internet lore or parrot what they've herd about soft swaged lead hbwc's. I have a smaller/narrower version of that 44cal hb pin that has no problem with loads in the 25,000psi/30,000psi range doing +/- 1600fps in a 14" contender bbl.

The 3 bullets on the right are all 35cal's that weigh 148gr.
NN4tThP.jpg

When cast with 14bhn/15bhn alloy all 3 of them can be loaded with 14.0gr of 2400 in 357 cases when using 1.4xx" oal's for all 3 bullets.
 
What I have learned while shooting Berry's Plated bullets. The Hollow Base bullet and the Flat base bullet of the same weight, the Hollow Base bullet is longer than the Flat Base but they get loaded to the same length. Because of the hollow base they load to the same volume inside the case so the only real difference is the bearing surface and with that the difference is marginal.

I load both and shoot both, in the .356" 115gr RN, .356" 124gr. RN & FP, .452" 200gr FP and load them all the same.

Others may have found different results but this has been my experience and I shoot a lot of the Hollow Base.
 
All of the load data I see is for Berry's HBRN. Would the data be the same for flat base bullets?
Yes, BUT !!!
You need to understand the rules... Both bullets have the same weight and are of the same construction (plated lead). So they will use the same Load Data. But, they vary ever so slightly in their plating thickness, and of course barrel contact length, so there will be minor differences. All these minor differences will be found by beginning your load testing at lower loads and working up in small increments.

• If this is your first loading experience with Berry bullets, then we would insist you go all the way back to Starting Load.

• However, if you have previous experience and notes from the other Berry bullet, the differences are so minor between these 2 bullets that you may only need to step back 0.2gr from your previous loads.

In my testing the final loads came up as 0.1gr difference in my gun between the 2 Berry products. You'll need to do your own testing, or course, in your gun to verify.

Hope this helps.
 
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In my experience, there are differences in flat bottom bullets and hollow base bullets.

With .38 Special Wadcutter ammunition, loads over a certain loading (more pressure) would literally blow the 'skirt' off. (The bullet is a swaged lead bullet.) It may or may not have been sufficient to damage the gun from the pressure, it was counterproductive for accuracy. Go figure. There was conjecture about such loads being 'dangerously' high and also from the shards of the bullet "skirt" believed to lodge in the barrel or barrel gap. I am unaware of any occurrences of such, but some folks will always see the down side.

Jacketed bullets should be a bit tougher and less likely to fragment the skirt, but the point of the hollow base bullet is for the bullet to fill out the bore for maximum efficiency and accuracy.

Rifle bullets usually have a rather small hollow and are very difficult to foul up.

Bullets are not dependent solely on weight for loading data. The internal structure can have great influence on how hard it is to push the bullet in question down the barrel in question. Simply, consider what allow is used for the lead core: A 'hard' core would be more resistant than a 'soft' core. Solid bronze or copper bullets would be more so.

I suggest that bullets of similar construction would follow the weight criteria for load data.

All that being said, begin with the lowest minimal load when in doubt and work up until good sense and accuracy declare a winner. I find it perfectly acceptable to stay under maximum loadings.
 
So I went to the bench and got my printed Western Powder data and here is what I found;

9mm. Accurate #2
115gr Berry's RN, AA #2, 4.2 - 4.7gr. the only published data for this bullet and this powder

124gr Berry's HBFP, AA#2, 3.7 - 4.1gr @ 1.060"
124gr Berry's RN, AA#2, 4.0 - 4.4gr @ 1.160

9mm Ramshot Silhouette
115gr Berry's RN, Silhouette, 5.5 - 6.2 again only one load listed

124gr HBFP, 4.8 - 5.4gr @1.060"
124gr RN, 5.2 - 5.8 @1.160"

45ACPAccurate #2
200gr Berry's HP, 5.3 - 6.3 @ 1.205"
200gr Berry's FP, 5.4 - 6.3 @ 1.205"
200gr Berry's SWC, 5.1 - 6.0 @ 1.212"

The same variation holds true with Silhouette and AA@5 with no published data for the Hollow Base bullet for the 45acp.
I am assuming that the question pertains to comparing Berry's bullets to other Berry's bullets as western also lists other bullets with separate data and in some instances the data isn't even close.

Westerns available published data for Berry's plated bullets in one reason I have moved primarily to Western powders.
 
My S&W M&P loved the .452 Berry's 185 gr. HBRN bullets. I sold the pistol to my son-in-law, and bought a 1911 in 45 ACP. Those same bullets patterned instead of grouping them. So soon afterwards the 185 grain bullets went with the pistol that I sold .
 
Assuming the same weight and loaded to the same length or longer it should work fine. As usually best practice is to start low and work up when you make minor changes in a load like this. What specific bullet are you going to use. There may be data in other sources using that exact bullet.
I'm using Berry's RN with a flat base.
 
Yes, BUT !!!
You need to understand the rules... Both bullets have the same weight and are of the same construction (plated lead). So they will use the same Load Data. But, they vary ever so slightly in their plating thickness, and of course barrel contact length, so there will be minor differences. All these minor differences will be found by beginning your load testing at lower loads and working up in small increments.

• If this is your first loading experience with Berry bullets, then we would insist you go all the way back to Starting Load.

• However, if you have previous experience and notes from the other Berry bullet, the differences are so minor between these 2 bullets that you may only need to step back 0.2gr from your previous loads.

In my testing the final loads came up as 0.1gr difference in my gun between the 2 Berry products. You'll need to do your own testing, or course, in your gun to verify.

Hope this helps.
That definitely helps. Thanks
 
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