Question about Metpate size

[MGySgt]

I am getting ready to order a new mold for my 45/70's (2 Marlin's and a Ruger #1). I know that the wisdom says fit each rifle with it's own bullet, but I can't afford that many molds and keeping them straight may even be harder.

Current bullet - MM 430gr GC Ogival Flat point 75% metplate with a nose lenght of .450. This bullet drops at .461+and is sized to .460.

3 different rifles (1895 Microgroove, Ruger #1 and Sharps repro) all shoot right around MOA day in and day out, some groups are very impressive on a good day when the moon and stars are aligned and I am holding my mouth right I can get 1/2 in groups at 100.

You would think that all 3 would have a velocity difference with the Sharps being the lowest - well that is not quit so. All 3 of them have to be loaded to around 1475 FPS to get good consistant groups. I thought my alloy was too soft air cooled (9 BHN), not so, I water dropped about 100 and sized and lubed them and after sitting for 3 days came up to 24 BHN. Same velocity range - 1475.

I have varried the amount of lube, changed the hardness, changed the powder (2400 and 3031) same results. I get to 1475 and things are just great. Go over 1500 and the groups open up.

Now for the question - What is a good metplate size for higher velocity?

50%
60%
????

I would like to raise the velocity up some - to around 1700+ to flaten out the trajectory some. Right now I have my sharps zeroed for 7 in high at 100 and 2 inches low at 175. 7 inches high at 100 sounds high but if you hold about a 1/3 way up the body to about 150+ on an ELK, you have one dead Elk.

I am going to have Dan at MM make me a mold on the RCBS 405 lines. I have some of Creekers in 430 grain GC and they shoot real good out of the Marlin GG even with the porting. Haven't finished the load out or chronoed it, but I know it is higher then MM bullet.

I would like to at least come close on the FP size this time!

The MM stays with the Sharps. I am looking for a bullet for the Marlins and the Ruger #1.

Thank you in advance for any light you good folks can shed on this.

Drew

[Bass Ackward]

I have varried the amount of lube, changed the hardness, changed the powder (2400 and 3031) same results. I get to 1475 and things are just great. Go over 1500 and the groups open up.

Now for the question - What is a good metplate size for higher velocity?

50%
60%
????

I would like to raise the velocity up some - to around 1700+ to flaten out the trajectory some. Right now I have my sharps zeroed for 7 in high at 100 and 2 inches low at 175. 7 inches high at 100 sounds high but if you hold about a 1/3 way up the body to about 150+ on an ELK, you have one dead Elk.

Drew

Drew,

I am a little confused at what you are asking. Meplat size mostly affects accuracy because it is unsupported nose weight. The more unsupported nose weight you have, the longer the bearing area needs to be to carry it. Think about that for a minute.

The reason that cast accuracy falls away at lower velocity levels with larger calibers at normal cast velocities is because of drive area on the bullet. A 30 caliber bullet with .004 rifling has a much larger percentage of the bullet's diameter to rotate it than a .458 with .004 tall rifling. So if you can't change any of your barrel properties, you need to change your bullet. Much is often made of 2X bearing area. Well, that is obtained at @ 150 grains in 30 caliber. The lowest weight I could design one in 458 and maintain a good hunting meplat was 430 grains. And that was with a 50% meplat.

The more unsupported nose weight you carry the heavier your bullet needs to be OR you start to lower the velocity ceiling. But you should be able to get fair groups (for hunting) at 1700 fps with almost any 400 grain design. 2400 throws too much pressure to do this velocity level. And maybe 3031 doesn't throw enough to get consistent ignition under your conditions. Split the difference and try some 10X and ACWW. Makes me smile.

[waksupi]

Bass Ackwards, lets look a the large meplate another way. Rather than a long unsupported nose, what if we have a shorter, more curved ogive?

[Bass Ackward]

Bass Ackwards, lets look a the large meplate another way. Rather than a long unsupported nose, what if we have a shorter, more curved ogive?

Ric,

A shorter more curved olgive helps increase the percentage of the bullet involved in the drive situation, but it hurts the ballistic coefficient. That's the trade off you face. As long as you are above the magic line, you are OK. Where the line is I don't know. If I am recommending for someone else, I want to be safe. If you look at the cast bullet mold lines that have survived the test of time for working in the widest percentage of guns available, look and see how many have super wide meplats.

Nope, about 60% is my limit for rifles and 70% for handguns at this date and time. Now that opinion could change tomorrow because it has in the past. And what changed it was a better understanding of metal hardness and how to produce higher velocities with softer mixes. And metal hardness rates higher in my book than does meplat size. Any recommendation I make is probably going to fall along those lines.

[MGySgt]

Bass - I knew that you would confuse me even more then I already am - Take it easy on this old retired Marine.

I have tried this bullet both hard and soft 9 and 24+ BRN - same results max velocity 1475 FPS. After 1500 the groups really start to open up. I stopped at 1550 or so with 4+ inch groups at 100 - not acceptable to me - that equatesout to over 8 inches at 200 with my scoped 45/70's.

I am shooting a 75% flat point. Great hunting bullet (IMHO) for my Sharps and limited chamber pressure, more velocity then the orig 45/70, and with the AC alloy the bullet mushrooms to about .95 in a bank of clay and sand and retains more then 400 grains. NO COMPLAINT with bullet performance. This would also work in my Marlins for a solid short range Brush load. I don't think that anything in North America could stand up to it, from Whitetale to Polar bear - Of course if I was going after other then Black bears I would HT it for deeper penetration.

I THINK my velocity limitation is the wide flat point - the darn thing looks like an over grown wad cutter! I am sure with some other powder I could get the same accuracy out of my Sharps at a lower velocity for a play round, although the 3031/dacron (41.5 gr) is real easy on the shoulder compared to some of my 45/70 and a Hornady 350 J flatpoint in my #1 or either of my Marlins.

I think that I need to drop the percentage of the FP down to 60 or 65% to get a good hunting bullet and more velocity. Creeker's 430 gr looks about in that range, but I have not completed the load nor shot at 175yds with it. Running out of time before I leave for CO. I will do some more testing when I get back as long as I have some of them left.

I am trying, through yours and others vast experience here, to shorten or confirm my thoughts and tests.

What metplate size is a good compromize for hunting for accuracy and velocity and still retain the effect that a WFN gives you?

Am I making sense or off in left field some place?

Still Confused - Drew

AKA - Dumb Old Retired Marine that sometimes needs a keeper!

[felix]

Today was my first time out shooting for real in about two years. It just so happens I had a mission today, and that was to compare two boolits in heavy wind: the Bator 22, and the Lyman target (225646). The Bator has 80 percent bearing length with a 50 percent meplat for 51 grains. The Lyman at 62 grains has no more than 50 percent bearing with a 10 percent meplat at the end of a 50 percent bore/land riding portion which does not engrave in my bench gun. The distance was 100-120 yards at small targets like rocks, shiney water drops on leaves, and representative dirt clods. These targets ranged in size from 1/8 inch to about 1 inch. The smaller targets were targeted when the wind was relatively quiet. The car roof was jumpy when the wind was up, and required a larger target so the target could be hit. Using weeds as wind flags was entirely useless with the car so jumpy. Result: about 33 percent hits showed that the Bator boolit could not hold a candle to the target boolit in the windy conditions. About 75 percent hits occured with the Lyman boolit. Both boolits were about identical in accuracy when the wind was consistent (not puffy; not jumpy) or during the time when the wind was not significant (about every 5 minutes for 15 seconds each). ... felix

[waksupi]

Felix, your post hit my funny bone. As good a benchrest shooter as you are, you were still probably shooting better than 90% of us from a solid bench, when you're shooting from an improvised rest on a wind shaken car!

[Bullshop]

Felix
Interesting stuff yes sir, what cartridge were ya shootin? I have both those boolits too. I cant seem to get the Bator to want to go fast with good accuracy. The Lyman target no problem. The Bator is a good boolit for hornets with short magazine and slow twist as its fairly heavy but short, but as I said no joy for speed with that one for me. I have an interesting one you should try. Its from Walt Melander and kind of a cross between the bator and the Lyman target. In WW it drops about 55gn has the same bearing length as the Bator but the pointy nose of the Lyman with a Loveren style body. This is the one Jr has been using for some pretty speedy velocities from his Rem 788 223. That is about the finest boolit shootin 22 I have ever seen. Dont remember how the little bugger talked me out of it. Be warned if ya ever do some swappin with him he has a way to make ya think your holdin the better part of the wish bone but when its done your holdin the short stick. Takes after his Mama he does. Well lemy know if ya wana try some of them NEI boolits, no charge a cource and I would be honored.
BIC/BS

[Bass Ackward]

What metplate size is a good compromize for hunting for accuracy and velocity and still retain the effect that a WFN gives you?

I stopped at 1550 or so with 4+ inch groups at 100 - not acceptable to me - that equatesout to over 8 inches at 200 with my scoped 45/70's.



Drew,

I find that my rifle that my 430 grain bullet with 50% meplat performs as well on deer as my 375 grain LBT, with 70% meplat using 14 BHN or less. Above that hardness, the LBT is only slightly more effective. So I guess it really is going to come down to how hard you have to go to get the accuracy you want. 60% is a nice comprimise. My 430 grain above was really designed more for accuracy purposes. Just remember, never use more meplat than you need to perform the function you want. Hope this answers your question.

You might be right though. Dan was having trouble and getting 5" groups from his best load at 100 yards with his 92 in 357 Mag. I told him I thought meplat was his problem as he was shooting an 80% mepper. He cut everything the same and dropped it to 75% and his groups dropped to 3". He stopped there because he was going after moose. I hope he continues this next summer as a test.

[Bass Ackward]

Felix,

I have pretty much tested this, but in 30 caliber. I have a 160 grain LBT spitzer and I made a 165 grain with the same exact measurements except I gave it a 60% meplat. That raised it to about 164 grains with the same mix. Theoretically the fit should be very close to the same.

The spitzer is a far better high velocity bullet. The 60% mepper is more accurate below 2000 fps. Both have the same horizontal deflection at 100 yards in wind. Now that may change farther out as the mepper loses more velocity, but that was that in 30 caliber. Wind was @ 15 MPH. I don't have many days with wind here.

What would have been interresting was if the weights had been reversed. If the Bator was 62 grain and the Lyman had been 51. The better the BC of any bullet, the better it is going to hold velocity and have less time to be affected by wind. But bullet weight alone makes a BIG difference in wind. On days that my 223 is strewn all across the target, my 45s go in the same place. They may be an inch or so off center, but when inventory is taken, they all went there.

[felix]

I agree, BA. The weight of the two styles of boolits should have been reversed for a genuine accuracy test, but then we would be confused on which boolit to shoot on which kind of day should they both be equal at the typical range for 22s at 2400 fps or so. ... felix

[felix]

Yeah, man! Send me a 100 or so of Walt's boolits, please! Why? Because Sundog and I are thinking of having David Mos make us a four banger coppered-iron mold (to hold heat, mainly) the size of the typical two banger (appropriate size for us older guys) and we want to have a good boolit design to warrent the cost. David is not cheap to say the least, but his quality is second to none. Should we go through with this, we would have several molds made for board members, with Sundog and me supplying the funds up front. David will have to be talked into doing this because his real forte is in making bump dies. Maybe if the design we come up with warrents it, we might have him make them for this boolit design as a package consisting of mold and commensurate die. ... felix

222 ackley is the bench gun's caliber, 14 twist. This case has no noticable case volume improvement, but the sharp shoulder eliminates case stretch entirely. The gun is heavy varmit class with the barrel tight necked at 246. 24X Leupold target scope of the 70's vintage. The gun is no longer competitive on the bench circuit, having over 10K rounds through it. ... felix

[BABore]

No disrespect, but all the talk has been on the bullet design and metaplat size. I think that's a smaller issue. Granted a large metaplat is said to be less accurate, but I haven't found that to be the case in my guns.

Felix,

What was the load you were using?

I have shot a bunch of Cast Performance and Jae BoK Youngs gas checked hard cast (21-23 Bhn) out of my 450 Marlin guide gun. Weights range from 405 to 550 grain and most had 73% plus metaplats. Velocities were at the maximum for the Marlin action with the 400ish bullets clocking 1,800 to 1,900 fps and the 550's at 1,500. This is from an 18.5 inch ported barrel. One of my favorite loads for Jae Bok Youngs 420 gr WFNGC Crater Lite is 49 grs of H322 and a Federal 210M primer. Accuracy is running just above MOA all the way out to 300 yards with an ES in single digits.The metaplat on this bullet is 0.36 or 79%. There's a lot of data to be had on the Marlinowners forum for these higher end loads. Most have found the H322, H335, H4198, Benchmark, and Reloder 7 to be the powders of choice. There are a few who load these bullets in their #1 and get velocities in the 2,000 to 2,200 fps range. Both Buffalo Bore and Garretts load big metaplat bullets commercially at high velocity and have a proven track record.

I don't think you have anything to worry about with your bullet design. I'm planning to order almost the same mold from MM. If you get too frustrated with yours, give me a call, I'll buy it. :smile:

[felix]

BAB, the meplat size can be significantly larger with the heavier boolits for the same accuracy. The actual weight of a boolit plays a significant role. Consider at your distance of 300 yards, the Lyman 454190 pointed cowboy boolit at 250 grains very well could be as accurate as your WFN at 400 grains. This is the same conjecture BA made, and I agree with him (and you) after considering the bout with the 22 I had yesterday. So, the moral of the story is to make sure your twist can handle a flatter and longer boolit. 18 twist for the 45s has proven to be ideal for 1200 yard stunts with the 500 plus grainer flat noses. ... felix

[Bullshop]

Felix
Let me know where you want them to go. Keep me informed about the mould project. I probably cant afford it but by some freak occurance in the natural order of things its possible I could have $$$ at the right time and place God willing.
BIC/BS

[The Nyack Kid]

To Quote MGySgt

I would like to raise the velocity up some - to around 1700+ to flaten out the trajectory some.

I have tried this bullet both hard and soft 9 and 24+ BRN - same results max velocity 1475 FPS. After 1500 the groups really start to open up. I stopped at 1550 or so with 4+ inch groups at 100 - not acceptable to me - that equatesout to over 8 inches at 200 with my scoped 45/70's

I would recommend that you try this boolit @ 1700 out of all your rifles before condeming it all together .

I have a Mountain mold that has a 90% meplat and wheighs in at 460 grs
this boolit likes to be diven over 1700 fps out of my winny 86 . i get one inch groups @1750 fps and lousy groups at 1630 fps

also you didn't mention if you have a gascheck or plain base boolit .
If you use a hard boolit with a wide meplat you aren't going to give up anything preformance wise on big game vs soft cast

Couse this could be the excuce needed to justify a new mold.
Just my $.02 which i what back seeing what fuel prices are now .

[MGySgt]

To Quote MGySgt

I would recommend that you try this boolit @ 1700 out of all your rifles before condeming it all together .

also you didn't mention if you have a gascheck or plain base boolit .
If you use a hard boolit with a wide meplat you aren't going to give up anything preformance wise on big game vs soft cast

.
Nyak - I have tried it at over 1700 out of my Ruger #1 and had to back it down to under 1500 to get MOA - was 4 plus with both 4198's and 3031.

The meplate size is .350, just re measured it.

It is a GC with a .450 nose and .100 front band ogival FP. no step/shoulder.

As the chamber presure is at max for my IAB 45/90 and at MOA - this mold will be used for a number of years to come.

But my R#1 and my Marlin Guide Gun I have to seat deep, no real problem for the #1, but I need a crimp for the Marlins. So I need a new mold anyway.

I want a design that would chamber without triming back shorter then the Trim to lenght and allow me to go higher velocity.

I still have some of Creeker's 430 gr GC that is on the same lines as the RCBS 405 and I may try and duplicate it if it does what I want. Getting too close to Colorado time (12 days) so I have put that on the backburner until I get back. Taking the Sharps repro and spending my time on it. Just loaded 40 more to play this tomorrow!

I think the sights are finally set - going to shoot 175 tomorrow and verify that it is 3 inches low.

Drew

[The Nyack Kid]

ok im geting a better picture now . my bad .i see in your first post that you said it was a gascheck .
What is the max OAL length that the marlin will take and which rifle has the sortest throat ? the rates of twist are differant ? mmm i feel for you. trying to find a boolit that fits in all three guns and is accurate at the same time , at the desired velocity to boot ,could be quite the PITA .

keep up the good fight

[The Nyack Kid]

in my (very little ) book WFN = .360 + or - alittle LFN = .330 + or - alittle asumming a hard boolit ,the LFN will have to be going faster to have the same sized wound channal as a WFN . there is a neat wound channal calculator over at the Beartooth bullet site that will answer a bounch of questions .
LFN will have the better B.C. . = easier to keep the speed up at longer ranges.

[MGySgt]

What is the max OAL length that the marlin will take and which rifle has the sortest throat ?

keep up the good fight

OAL isn't the problem with the Marlin GG - it is throat - like the #1. If I use the crimp groove - it jams into the rifling and the lever can be hard to close if the ogive is just a hair larger due to my casting.

I am going to re-measure all 3 chambers (#1 and both Marlins). I will probably wind up with 2 different molds, one for the #1 and one for GG and leave the Microgroove for that ugly word - Jacketed or just sell it. Hard to justify the 1895 and 1895 GG when I am out of room in the gun safe and I want another Sharps and the GG will do everything I want with the lever.

Decisions - Decisions - Decisions!

Currently with the GC and a soft alloy - I am not getting any leading. Even when I had the #1 over 1700 there was no leading so the soft alloy should be fine. If not I will HT them and bring them up over 24 BRN - I have over 1,000 punds of this alloy so I will be shooting it for a long time.

I am trying to eliminate purchasing another mold that is in restricted velocity range like my current one due to metplate size.

From what I read about 60-65% is a good compromise between velocity - accuracy - and wound channel. I want to keep the weight over 400 grains.

Drew