AJC1
Member
It seems if you have an overbore or many guns in the same caliber this might be an awesome option. I have never loaded or shot any but found myself curious. Does anyone cast hollowbases? Intrested in any experiences.
It seems if you have an overbore or many guns in the same caliber this might be an awesome option.
Some guns you just dont rebarrel like an all original 7.7 arasakaWhy would this matter? I have many guns in the same caliber but can't understand why I would want to use hollow base bullets because of that.
Do you own any old guns?
And what does overbore have to do with it?
I was thinking rifle 45/70. Low power trailboss loads may opterate better and improve accuracy. Unique and 2400 loads may also benefit. No idea but curious.Rifle or pistol? Blackpowder folks do.
I believe the idea is a hollow base bullet will obturate better to fit an oversize bore. Not sure how well that works in practice with a copper plated projectile, but in theory they may offer better accuracy with oversize bores, and/or better consistentcy across a variety of barrels with slight variations in diameterWhy would this matter? I have many guns in the same caliber but can't understand why I would want to use hollow base bullets because of that.
And what does overbore have to do with it?
Same caliber, but barrel dimensions do vary. If one had a 38 Special hollow based bullet load it would work in barrels with groove diameters from, .356" to .358". (I have 4, 38 cal revolvers and cylinder throats vary .003" and barrel groove diameters up to .358".)...Why would this matter? I have many guns in the same caliber but can't understand why I would want to use hollow base bullets because of that.
And what does overbore have to do with it?
Perhaps a little history of hollow base bullet development/evolution will shed some light on the discussion and help the OP.I have shot a lot of Barry's HBTP 9mm bullets for plinking loads and they shot well enough. Nothing shoots as accurate as a jacketed bullet due to the tighter manufacturing tolerances (weight, diameter, etc). That may be the reason the concept of hollow back bullets (except 38/357) hasn't been adopted by any of the major bullet manufactures. I think, for the hollow base to be effective, you also need to be using a soft lead bullet and a very light load such as what guys are loading in 38 special for bullseye to keep from blowing out the bullet.
Berry's MFG said:we try and get better every chance we get. Over the years we've added to the thickness of the plating, restrike every bullet now, and are holding better weight tolerances by purchasing specifically alloyed lead from the foundry that is able to give us the same alloy every truckload.
Berry's MFG said:We do go to a .356" with the 9mm bullets, all of our pistol bullets are .001" over just like a cast lead bullet.
Berry's MFG said:We use carbide re-strike dies that helps us keep the uniformity on the final size. When you measure the bullet use a mic at the base. Our 9mm bullets are .356 + or - .0005"
We have a plus or minus .0005" to give us a bit of room with the dies. Our die manufacture gives us a plus or minus of the .0005", wear is a factor as well.
Berry's MFG said:I have never cut through the plating with my crimp die. I have never shed copper when firing my .357 Mag or 10mm beyond the 1200FPS. I hear a lot about limited speeds in the .45 due to the plating, but have never seen chronographed data to support it. We have added plating thickness to all of our bullets over the last 10 years to a point that the current bullets are a very different animal.
Berry's MFG said:That 1200 fps mark is a general rule on the pistol calibers ... have some proto's in the 124gr RN hollow base with a thicker plate that should take care of the issues you guys are seeing in trying to punish our standard bullets.
Berry's MFG said:Depending on caliber our plating is no less than .006" and goes up to .012" thick.
Speer TMJ bullets are a plated bullet with an even thicker plating coming close to a jacket at about .015" in thickness.
Berry's MFG said:New bullet today
IMHO, Berry's MFG's push for developing hollow base plated bullets with thicker plating was to improve their regular plated solid base bullets to result in greater accuracy, even when using max jacketed load data.It seems if you have an overbore or many guns in the same caliber this might be an awesome option. I have never loaded or shot any but found myself curious. Who's loading hollow base bullets now. Interested in any experiences.
I was inclined to think that HB bullets were to be loaded very low velocity to prevent ring damage. Your points were very helpful and I never saw the provided Berry's information before. Always in the search for complete understanding. I had been reading the benifits of the Hollow base mini ball and trying to find out if those improvements would apply to low velocity large caliber rounds like the 45/70. Its not like that round is exactly modern.Perhaps a little history of hollow base bullet development or evolution will shed some light on the discussion and help the OP.
If I recall correctly, Berry's Manufacturing tested several things to improve accuracy of their plated bullets like double striking (sizing) to produce more rounded bullet base, etc. Here's comment from Jay Phillips who is no longer working with Berry's MFG - https://www.thehighroad.org/index.php?threads/plated-bullets.588827/page-2#post-7271984
While most other plated bullet manufacturers sized their bullet same as jacketed bullet diameters, one of the things Berry's MFG tested that was effective was sizing the diameter of bullets larger (.001" larger like lead bullets) to better seal with the barrel to produce more consistent chamber pressures -https://www.thehighroad.org/index.p...berrys-plated-124grn-9mm.550411/#post-6813199
https://www.thehighroad.org/index.php?threads/berry-plated-bullets.532751/page-3#post-6630850
I shot USPSA in the 90s and used Montana Gold jacketed bullets exclusively for match rounds and Berry's plated bullets for practice rounds as they were much cheaper and shot more accurate than other brand plated bullets. But my experience with shooting various brand plated bullets was that plated bullets started to lose accuracy at higher than mid-rang jacketed load data (And why thicker plated bullets were developed) and best of "regular/standard" plated bullet accuracy never came close to average jacketed bullet accuracy. When I asked my bullseye match shooting reloading mentor why, he pointed out that lead base of FMJ would better expand to seal with the barrel (Like Minié ball design) while plated bullets with rounded base would leak more gas, especially when sized smaller at jacketed diameters of .355" and shot from .356"+ groove diameter barrels.
Another factor I found reloading plated bullets was many plated bullet manufacturers used softer lead alloy core and using too much taper crimp would reduce the diameter of the bullet while brass spring back would reduce neck tension which would stack on top of gas leakage from jacketed diameter sizing to reduce accuracy further. So when using plated bullets, I have been recommending minimal to no taper crimp (.022" added to the diameter of bullet as max amount of taper crimp).
To improve bullet base deformation/expansion and to better seal with the barrel, some bullet manufacturers "dished" or used concave bullet base or in the case of Zero/RMR, used larger sizing of (.3555"/.356) - https://www.thehighroad.org/index.p...re-sized-the-same.818806/page-2#post-10567453
Below comparison picture shows (From left to right) various 115 gr FMJ RN from Zero, RMR, Winchester (with skirt base/sharp rim), Everglades (dished base) and Federal (hollow base) - NOTE that Federal hollow base FMJ shows longer bullet length with longer bullet base/bearing surface to better engage rifling.
And Speer TMJ (Trademark Total Metal Jacket) thick plated bullets use distinctive dished base with clear circular stamping - https://www.thehighroad.org/index.php?threads/starting-load-for-147-gr-9mm.870683/#post-11549553
Here's Jay Phillips' comment on plating failure - https://www.thehighroad.org/index.p...-berrys-bullets-question.437798/#post-6697276
But to address the accuracy issue of regular plated (Around .004" thickness copper plating with 1200 fps max velocity limitation, Berry's MFG developed and tested hollow base bullet with thicker copper plating - https://www.thehighroad.org/index.p...rys-plated-bullets.548232/page-3#post-6808876
And Berry's MFG produced Hollow Base RN with thicker plating of .006"-.012" with 1500 fps rating - https://www.thehighroad.org/index.p...-jacketed-or-just-plated.759800/#post-9589491
And the birth of Berry's HBRN-TP bullets - https://www.thehighroad.org/index.p...r-hollow-base-rn-for-9mm.581070/#post-7169773
Below are comparison pictures of (From left to right) Berry's regular plated 115 gr RN bullet with rounded solid base, 124 gr Hollow Base RN with thicker plating, 115 gr HBRN-TP and Winchester 115 gr FMJ RN with sharp skirt (Likely meant to better capture expanding gas like dished/concave bullet base some plated bullet manufacturers use like Speer TMJ) - Notice that 115 gr HBRN-TP produces longer bullet length compared to 115 gr Regular RN solid base for longer bullet base/bearing surface for better engagement with rifling (And greater rotational stability in flight for smaller groups as experienced by many users of Berry's HBRN-TP bullets).
But notice below that Berry's hollow base is not a true hollow base like the Federal 115 gr FMJ HB bullet shown below left with thinner skirt. Jay Phillips from Berry's MFG explained that this smaller hollow base with thicker skirt was to prevent skirt separation from core - https://www.thehighroad.org/index.php?threads/best-copper-plated-full-wadcutter.536271/#post-6662715
IMHO, Berry's MFG's push for developing hollow base plated bullets with thicker plating was to improve their regular plated solid base bullets to result in greater accuracy, even when using max jacketed load data.
It is my opinion only that Berry's hollow base bullets, while producing better than average plated bullet performance in terms of accuracy, may not expand the bullet base/skirt enough to compensate for oversized barrels and larger sized bullets or true hollow base FMJ may address the oversized barrel issue.
I hope this helped.