Hollow back bullets, .45 ACP [Archive] - Glock Talk

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Boxerglocker
09-01-2010, 14:51
Just got some Bear Creek hollow back 200g bullets in .45 ACP to try out in my Kimber.

The plan is to stick with WST, as this is a moly coated LRN.

Range load 4.5 - 5.0 at 1.25 OAL based on this Hodgon data

Bullet Weight (Gr.) Manufacturer Powder Bullet Dia.
200 GR. CAST LSWC Winchester WST .451"

C.O.L. Grs. Vel. (ft/s) Pressure Grs. Vel. (ft/s) Pressure
1.225" 4.4 830 15,400 CUP 5.1 910 19,900

Anyone have any experience with these bullets? What about the COL, does the hollow back affect pressures/velocities drastically.

PCJim
09-01-2010, 15:57
Boxer, I've no experience with that particular bullet. Just thinking about the design, I would think that max pressure would increase slightly. The design extends the sides while providing a concave base to compensate. Total weight remains neutral. However, those extended sides will create more friction against the bore, thus creating additional pressure.

How much, who knows? You will though after you chronograph the rounds. Let us know, as I'm curious myself. I was recently sent a sample of a new 9mm projectile design for testing from one of the suppliers that I use. It also has a hollow base design. I haven't yet had the opportunity to get the Chrony out to field test them.

squirreld
09-01-2010, 16:08
let us know how they shoot.

fredj338
09-01-2010, 16:37
Boxer, I've no experience with that particular bullet. Just thinking about the design, I would think that max pressure would increase slightly. The design extends the sides while providing a concave base to compensate. Total weight remains neutral. However, those extended sides will create more friction against the bore, thus creating additional pressure.

How much, who knows? You will though after you chronograph the rounds. Let us know, as I'm curious myself. I was recently sent a sample of a new 9mm projectile design for testing from one of the suppliers that I use. It also has a hollow base design. I haven't yet had the opportunity to get the Chrony out to field test them.

I've not loaded those, but the Berry's HBRN shows slightly less pressure than an equiv solid. The slight extra bearing length is offest by the greater volumn now inside the case. Note, you do NOT want to drive them too fast. The "skirt" that is now your bearing surface can blow out as it leaves the muzzle & accuracy goes to hell. Tried this w/ some 155gr Berry's in the 40, best run under 900fps.

32dgrz
09-01-2010, 17:06
I shoot the Berry 185 HBRNDS with WST. I use 5.0 at 1.240. Don't know if that helps

Blaster
09-01-2010, 18:39
I have loaded a bunch of the Bear Creek 200 grain RNHB bullets. I used the same charge weight of Unique that I was using for their 200 grain SWC. Right around 6.2 to 6.4 grains.

I shot them out of my Glock 21 and Glock 30 and they performed perfectly.

PCJim
09-01-2010, 19:32
Fred, the "less pressure" finding is interesting, especially provided the same profile bullets are seated to the same COL. My thought was that given the same bullet weight and finished round COL for a similar profile (FMJ in your case), the volume inside the case would have to be the same. That is, unless they are using a differing ratio of lead:copper in one of the bullets. Otherwise, with similar ratios of lead:copper, there should not be more volume available - extended sides and hollow base v shorter sides and flat base. The additional length of the sides resulting in increased bearing surface would tend to increase pressure, again all other parameters being the same.

This is just my layman's thinking cap working. I certainly do not consider myself an expert in munitions.

Anyway, Boxer, we need feedback after you have a chance to test those rounds.

Boxerglocker
09-01-2010, 21:09
Fred, the "less pressure" finding is interesting, especially provided the same profile bullets are seated to the same COL. My thought was that given the same bullet weight and finished round COL for a similar profile (FMJ in your case), the volume inside the case would have to be the same. That is, unless they are using a differing ratio of lead:copper in one of the bullets. Otherwise, with similar ratios of lead:copper, there should not be more volume available - extended sides and hollow base v shorter sides and flat base. The additional length of the sides resulting in increased bearing surface would tend to increase pressure, again all other parameters being the same.

This is just my layman's thinking cap working. I certainly do not consider myself an expert in munitions.

Anyway, Boxer, we need feedback after you have a chance to test those rounds.


Yeah, I'm on the same boat as you Jim, but at the same time perhaps over thinking it.
Alot of guys in our IDPA club are using these BC HB 200's for .45 since one of the members became a distributer. They all have had great sucess with them but using other powders mainly Unique.
I'm gonna give the box of 500 I picked a try with WST and run them through the chrono.
Staying below 900 fps is my intent to run them right at about 173-175 PF for CDP division.
I'll let you guys know how they work out.

fredj338
09-02-2010, 01:59
Fred, the "less pressure" finding is interesting, especially provided the same profile bullets are seated to the same COL. My thought was that given the same bullet weight and finished round COL for a similar profile (FMJ in your case), the volume inside the case would have to be the same. That is, unless they are using a differing ratio of lead:copper in one of the bullets. Otherwise, with similar ratios of lead:copper, there should not be more volume available - extended sides and hollow base v shorter sides and flat base. The additional length of the sides resulting in increased bearing surface would tend to increase pressure, again all other parameters being the same.

This is just my layman's thinking cap working. I certainly do not consider myself an expert in munitions.

Anyway, Boxer, we need feedback after you have a chance to test those rounds.
SInce there are precious few 185grRN bullet available to compare to the HB Berry, I can only relate what I exp using the XTP vs the Berry's. The Berry's does seat a bit further out & has the HB, which increases internal volumn. The bearing surface may be a bit longer, but the base not being solid certianly can't recieve pressures the same. If you take a 185gr bullet & stretch it out to be the exact same length as a 230gr, the HB void will be quite large, adding to the internal volumn, reducing pressures. That pretty much negates any slight bearing length.
Just my layman's thoughts. :supergrin:The chronograph shows much lower vel than using say a 185grXTP w/ the same charge wt, but shorter OAL.

gwalchmai
09-02-2010, 08:19
I've shot a few thousand of the BC 200gr HBRNs in .45 ACP and .45 Colt. I couldn't tell any difference between them and BC's 200gr SWCs. I don't think the hollow base makes any difference in pressures and the walls are too thick to aid obturation (esp in target loads). They shoot fine, though.