Help deciding between 9mm MP molds & bevel vs flat base?

[Omni]

A big question is how important is bevel vs flat base in 9mm bullets/molds?

Is casting actually easier with BB molds?

Is accuracy better with Flat/Plain base molds?

Is barrel leading more/less likely with either?


The first two are 135gr molds one flat base one is bevel base. This is a little heavier than the 120-130grain range I was planning on initially, but was recommended. Could also use in 38/357 loads, but don't own or reload those calibers currently.

135gr Flat Round Nose, Flat base, 8 Cavity AL No Lube Groove Mold
https://www.mp-molds.com/product/357-359-135-flat-round-nose-flat-base-8-cavity-aluminum-no-lube-groove-mold/

135gr Flat round nose, BB 8 cavity AL no lube groove mold
https://www.mp-molds.com/product/357-135-flat-round-nose-bb-8-cavity-al-no-lube-groove-mold

125gr Flat Round Nose, Flat Base, 8 Cavity AL No Lube Groove Mold
https://www.mp-molds.com/product/357-359-125-flat-round-nose-flat-base-8-cavity-aluminum-no-lube-groove-mold
I lean towards 125gr weight to save on lead but MP doesn't offer any 125gr NLG molds with bevel bases...

130gr TC BB 8 Cavity AL No Lube Groove Mold
https://www.mp-molds.com/product/9mm-130-bb-8-cavity-aluminum-no-lube-groove-mold
I like the Truncated cone design mimicking the 125gr TC Blue Bullets I've used. Weight is a decent compromise. Only available in .358"; then adding Eastwood powder coat I plan to size down to .357" which should be fine?

[challenger_i]

I prefer flat base. Bevel-base is, to my belief, to facilitate seating the bullet. If this is an issue, slightly bell the case mouth. A bevel-base will allow the gases to more quickly erode the bullet base, causing gas cutting and, consequently, increased leading.

[wv109323]

In my experience there is no accuracy difference between bevel base and flat base. In 45 ACP you have the H&G 068 and 069. The bevel base was made to prevent lead shaving when aligning and seating the boolit. There is a old wife's tale that the bevel base is more prone to lead barrels but lead hardness and barrel fitment override BB vs FB.

As a word of caution most 9mm pistols like a lead boolit larger than .356. I would buy a few commercial cast bullets to try before investing in a mold. It sounds like you will be powder coating so mold size may not be of prime importance.
Several 9mm chambers are cut for jacketed bullets that makes fitting and oversized bulletc next to impossible to fit and function in a semiauto with accurate results.
I have had five 9mm pistols and only one was agreeable with cast boolits. The ones that did not like cast boolits were CZ and Canik ( 2 of each) and a Tisas that will shoot anything. Good luck on your adventure. Getting a 9mm to shoot cast bullets has been the greatest adventure in over a 50 year career in reloading.

[Thumbcocker]

In my experience flat base works better with a lube sizer, less chance of lube getting on the bottom of the boolits. I don't know that ther is an accuracy difference.
I size 9mm boolits to .358 and they have chambered fine in: a Glick 19, 2 Browning high powers, a Walther P1, a Sig P365, and a Rock Island 1911. Be careful when crimping. Use enough taper crimp to remove the flair plus a bit. Over crimping will bulge the case. Remove your barrel and use it as a "plunk" gauge.

Sent from my SM-G960U using Tapatalk

[MT Gianni]

[QUOTE=Omni;5752377]A big question is how important is bevel vs flat base in 9mm bullets/molds?

Is casting actually easier with BB molds?No not really.

Is accuracy better with Flat/Plain base molds? If you are shooting at over 200 yards probably, If you are shooting at less than 50 yards no, not really.

Is barrel leading more/less likely with either? Leading is a problem of fit, alloy and barrel conditions, with lube and or coating being a big factor.

[Dave W.]

Have cast and shot both flat base and bevel base. Have not found accuracy or leading differences between the two. If the lube is too hot, bevel bases can get some lube around the base.

Over time I have gravitated to bevel bases for all pistol boolits.

[Dusty Bannister]

One reason for selecting the flat based bullet is observing the bullet base for flaws is much easier. The entire base is visible when the sprue plate is moved aside. Since perfect sharp base edges are the first thing that can be seen as part of the inspection, you know immediately if the bullet has the potential to fly well or not.

[kevin c]

I load a lot of 9mm for action pistol (10K would be a very slow year). I’ve always found it easier to seat bevel base bullets than flat base, no matter what amount of flare I put on the case mouth.

My go to is Miha’s bevel based 147 round nose.

[rockshooter]

The no lube groove are meant for powder coating probably. I prefer bevel-based because I think it gives the squished lead when sizing (and the PC) somewhere to go if there are no lube grooves. Also easier to put in the belled cases and since there is no lube to get on the beveled part, no reason not to use beveled bases.
Loren

[jdgabbard]

Back in the day there was a lot of speculation about bevel bases. Accuracy, leading, and all other sorts of issues were speculated to be the result of bevel based boolits. I believed this for some time. Then one day I shot some, and realized if there is a difference it's so small to be inconsequential. That said, I powder coat everything these days. And that results in loads that don't really lead at all. Accuracy hasn't done anything but gotten better overall throughout the years. So I would conclude that any design that works for you works. Regardless of whether it has a flat base or a bevel base.

Btw, that 125gr bullet is awesome. I use it in 9mm all the time. Though mine has a bevel base....

[Omni]

Thanks for the replies everyone. I fixed the links in my original posting as I figured out they were screwed up before...





Btw, that 125gr bullet is awesome. I use it in 9mm all the time. Though mine has a bevel base....

Is that bevel base an option he used to offer, I don't see any round flat nose 125gr molds with a bevel base option?
https://www.mp-molds.com/bullet-casting-equipment/?product_cat=&s=125&post_type=product

[jdgabbard]

Thanks for the replies everyone. I fixed the links in my original posting as I figured out they were screwed up before...





Is that bevel base an option he used to offer, I don't see any round flat nose 125gr molds with a bevel base option?
https://www.mp-molds.com/bullet-casting-equipment/?product_cat=&s=125&post_type=product

This is the specific bullet design I have. It’s still available:

https://www.mp-molds.com/product/mp-356-125-2r-6cav-bevel-base/

[Thin Man]

I have cast both flat and bevel base boolits. The strongest memory of their usage is that the bevel base patterns most often retain a ring of lube at the bottom of the boolit. That lube ring tends to smear on my hands and fingers, also on the top sides of the brass they are trying to seat them into. I find this annoying so I tend to stay away from them. I have even gone so far as to remove the bevel from several of my molds to make them solid base.

[dverna]

The only cast bullets we ever shot in the Ransom Rest were BB. Testing was at 50 yards with .38 Spl. The Remington 148 gr HBWC had a measurable accuracy advantage but I suspect that was due to it being a swaged bullet and thus more consistent. We did not weight sort the cast bullets.

A BB cast pistol bullet will deliver 50 shot groups of 3” at 50 yards. As a previous poster said, at pistol ranges if there is an accuracy advantage with a flat base bullet, it is a moot point. I find seating BB bullets easier so that is a plus for my needs.

None of my 9mm pistols are target quality. If a BB bullet is more prone to leading, I have not experienced it yet. BB seems to work but others may have different results.

[Targa]

125gr Flat Round Nose, Flat Base, 8 Cavity AL No Lube Groove Mold
https://www.mp-molds.com/product/357-359-125-flat-round-nose-flat-base-8-cavity-aluminum-no-lube-groove-mold
I lean towards 125gr weight to save on lead but MP doesn't offer any 125gr NLG molds with bevel bases...




I have this mold and it works very well. Accurate, feeds and cycles reliably in the six 9mm’s I own.

[justindad]

I find casting with a flat base easier. It is easy to see if the base is sharp or not. A bevel base may have incomplete fill out, but it’s hard to see because the bevel angle is broad. When casting too hot, you can get flashing at the base of a bevel base, which does not get cut off by the sizer the way it would with a flat base boolit. It takes more care to cast a perfect bevel base boolit than a perfect flat base boolit.

[Forrest r]

With the 9mm the solid bodied (no lube groove) bevel-based cast bullets are by far the most forgiving/easiest to reload. Doesn't matter if your die sizes the 9mm cases too small or if you don't have the correct expander button. The solid bevel base bullets will start straight and stay straight when seating them.
I cast this Mihec bullet for both the 9mm & the 38spl's.

https://www.mp-molds.com/product/359-135-swc-round-nose-6-cavity-mold/

I also cast this 125gr hp for the 9mm/38spl/357mag. It's a plain based bullet with a traditional lube groove.

https://www.mp-molds.com/product/mp-357-125-hp-pb-4-cav/

Both bullets get sized to .358" & do extremely well in everything I've tried them in.

I'd be more concerned with the design of the front of the bus (nose profile) and weight of the bullet.

[mehavey]

I've been watching this thread to reflect on the fact that (case properly flared)
I find my own cast/flat-based bullets are a whole lot easier to pre-seat absolutely
straight, . . . as compared to some of the commercial bevel base I've picked over
the years.

But that's just me I guess....:bigsmyl2:

[JonB_in_Glencoe]

A big question is how important is bevel vs flat base in 9mm bullets/molds?
>>>SNIP
without knowing the OP's shooting experience, answering this question is like the old Ford vs Chevy question.
If you are a beginner at loading/casting, the answer is, it doesn't matter.
.
I've always preferred flat base, so most of my molds are flat base. I have a couple bevel base molds, and they sure do cast easier and load easier. I've read discussions by people more experienced than myself, that bevel base molds will generally make a more perfect base, due to the base point of the boolit that contacts the barrel is not at the sprue plate junction, so theoretically it might be more accurate. The degree of increased accuracy, is likely not noticeable until a top marksmen is shooting to or beyond 100 yards.

[jdgabbard]

I have cast both flat and bevel base boolits. The strongest memory of their usage is that the bevel base patterns most often retain a ring of lube at the bottom of the boolit. That lube ring tends to smear on my hands and fingers, also on the top sides of the brass they are trying to seat them into. I find this annoying so I tend to stay away from them. I have even gone so far as to remove the bevel from several of my molds to make them solid base.


That is something to consider if you’re lubing your bullets!

I move to PCing for the most part. So that is why I’m a little less concerned about the bevel base, I’m sure. But if you are going to lube yours it makes sense to stick with a flat base.

[Forrest r]

without knowing the OP's shooting experience, answering this question is like the old Ford vs Chevy question.
If you are a beginner at loading/casting, the answer is, it doesn't matter.
.
I've always preferred flat base, so most of my molds are flat base. I have a couple bevel base molds, and they sure do cast easier and load easier. I've read discussions by people more experienced than myself, that bevel base molds will generally make a more perfect base, due to the base point of the boolit that contacts the barrel is not at the sprue plate junction, so theoretically it might be more accurate. The degree of increased accuracy, is likely not noticeable until a top marksmen is shooting to or beyond 100 yards.

Beveled bases also take finning out of play. More often than not finning doesn't have any major effect on accuracy. A bullet is swaged down in the bore and fins appear on the bullets base on flat based bullets. The amount of finning (larger diameter ='s more finning) and if a bullet wasn't sized strait or seated/shot straight. The amount of finning will be amplified, and bad things will start to happen.

It's hard to come up with examples of finning but here goes:
A 148gr hbwc cast with 8/9bhn alloy sized to .358" with a +/- 14,000psi 800fps load.
https://i.imgur.com/XVsDo3b.jpg

That bullets base has no finning and shows it was an excellent fit for that revolvers chambers and barrel.

Another hb cast bullet using the same 8/9bhn alloy, a hb hp swc (429422 with a hp added using a forester hp tool). The load was +/- 18,000psi/1000fps and the bullet was sized to .431" to fit the throats of the chambers in a ca bulldog. The barrel of that bulldog is tight .428"/.429". The loaded bullet with the hp and a recovered hp that mushroomed.
https://i.imgur.com/FTFbMo6.jpg

A side view of that same mushroomed hp. It clearly showed 2 things. The 1st was my pc'ing skilled were terrible. I wasn't letting the oven cycle back up to heat between batches and using minimum cure times. Ended up using pid controller and 20-minute cure times (up from 15 minutes) to resolve all of my pc'ing issues. The 2nd thing the picture shows an expanded jagged bullet base (finning) from the bullet being swaged down 3/1000th's+ in the bbl.
https://i.imgur.com/Swqedh0.jpg

+/- 40 years ago I did head-to-head testing casting h&g #50 wc's. 1 mold was a bb the other plain/flat based. Same alloy/sizing die/lube/cases/firearm/etc. Did a bunch of testing (over 800 shots/400 with each bullet) with different loads/powders/357",.358",.359" bullets, fully lubed, 2 lube grooves lubed, 1 lube groove lubed. All testing was done @ 50yds.

2 things came out of that testing:
The bb H&G #50 lubed in the bottom 2 lube grooves sized to .357" was "the" bullet.
No matter what load/lube/size bullet. The plain based bullet always had more fliers.

When I shoot at close range 25yds and closer. A bullets base doesn't matter. Nor does it matter if the targets are large. Take a 25yd load that looks pretty good accuracy wise and step out to the 50yd line and see what happens.

My last failure @ 50yds due to a bullets base. I cast some hb 35870's to test in a 9mm. It's a llloooonnnnggggg bodied bullet. The red bullet is the hb 35870 next to my favorite/standard 9mm bullet (green).
https://i.imgur.com/V87WlTN.jpg

As you see they both have the same oal to be able to chamber. But the hb 35870 sits a lot deep in the 9mm cases going into the web of the 9mm case. This caused too much distortion of the bullets base causing fliers.
https://i.imgur.com/77VoPsa.jpg

[20:1]

I prefer beveled base for 9mm, due in part the the abrupt inner case taper that can deform a flat bullet base, and also seems to make seating the bullet straight(er) easier. I had a 9mm accuracy issue at one point that led me to pull some bullets to remeasure bullet diameter, and see if there was anything else going on that I needed to deal with. I found I was seating my bullets (356402) a mite too deeply and the flat base was getting jammed (swaged, actually) into the inner case taper. These bullets were far more difficult to pull than normal and although I can't prove it I believe I was mainly getting erratic bullet release from the case because of the jammed bases. The fun part is that there's no firm set measurement for the inner case taper in 9mm, I measured a few different headstamps with constantly different results with nearly every case. So I threw in the towel and went to a bevelbased design I had on hand (356637) and started getting better results immediately. I do realize there is a weight difference between the two, but consistency was greatly improved. I did use Lymans published C.O.L. for both designs.

[charlie b]

I had a bevel base mold a long time ago. Was harder to cast well. More difficult to inspect the base. Collected a bit of lube that had to be wiped off before placing in the case. Did not change accuracy. After a few hundred bullets I got fed up with it and took it to the milling machine. Removed the bevel. Voila! Everything was back to 'easy' again.

These days i PC my pistol bullets. I'd be concerned about too much powder buildup in the bevel in an uneven fashion. That is a critical area for accuracy.

I've never shot HB bullets in my pistols so have not had the finning shown in pics above. Even flat bottom bullets that are a bit oversize for the bore do not show that kind of result.

[jdgabbard]

These days i PC my pistol bullets. I'd be concerned about too much powder buildup in the bevel in an uneven fashion. That is a critical area for accuracy.

It's less of an issue than you'd think. PC flows when curing, and levels out. horizontally as well as vertically. It has a high viscosity, making for a pretty uniform coverage. I've had zero issues with excessive buildup at the bevel base.

[Omni]

without knowing the OP's shooting experience, answering this question is like the old Ford vs Chevy question.
If you are a beginner at loading/casting, the answer is, it doesn't matter.

That's the conclusion I'm coming to. Everyone has there own opinion and preference. Accuracy data isn't convincing either way.

I'm leaning towards the bevel base to decrease base swaging in the tapered 9mm case. I'm not worried about lube in the bevel base since I'll be powder coating, in addition to bullets potentially seating straighter in a bullet feeding progressive press.

[Omni]

With the 9mm the solid bodied (no lube groove) bevel-based cast bullets are by far the most forgiving/easiest to reload. Doesn't matter if your die sizes the 9mm cases too small or if you don't have the correct expander button. The solid bevel base bullets will start straight and stay straight when seating them.

I also cast this 125gr hp for the 9mm/38spl/357mag. It's a plain based bullet with a traditional lube groove.

https://www.mp-molds.com/product/mp-357-125-hp-pb-4-cav/

I've been eyeing this mold specifically. I was originally wanting the MP 357-125 NLG mold but it seems Mihec just filled in the lubed design and the bullets come out ~5gr heavier. As long as the bullets drop free almost as easy and the decreased bearing surface isn't a hindrance I think the grooved design is more versatile. I do wish it was available in a bevel base option though. Since it isn't a very long projectile I shouldn't have to worry about the base swaging down in the case.

Everyone who shoots this bullet seems to love it and I love the versatility of the different pin options.

[Recycled bullet]

The mp357125 HP is an excellent bullet mold. I cast and powder coated for 9 mm and 38 Special.

[Omni]

For now I have a Lee six cavity 356-120-TC mold on the way which I found for $27.59 shipped. That's a little over what just the shipping would cost for a mold from MP to the West Coast. Hoping the cavities aren't undersized and are relatively uniform. I expect that using this mold will at least help me appreciate the extra quality from the more expensive molds or I'll get lucky and be satisfied for a few thousand bullets. If I decide to move on I can sell it and get my money back.

Ordered on 8/3, so I assume it's shipping on horseback due to the 8/14 delivery date...

[Taterhead]

Either work absolutely fine. In 9mm I have a slight preference a for a slight bevel. With the extra thickness of PC, the bevel gives the sized bullet somewhere to go.

I do also agree with 20:1 that the varying tapers of case interiors of 9mm cases work better with BB.

[Forrest r]

I've been eyeing this mold specifically. I was originally wanting the MP 357-125 NLG mold but it seems Mihec just filled in the lubed design and the bullets come out ~5gr heavier. As long as the bullets drop free almost as easy and the decreased bearing surface isn't a hindrance I think the grooved design is more versatile. I do wish it was available in a bevel base option though. Since it isn't a very long projectile I shouldn't have to worry about the base swaging down in the case.

Everyone who shoots this bullet seems to love it and I love the versatility of the different pin options.

It's my favorite 9mm bullet. People knock taurus pistols. myself I like the g2c and more importantly, my g2c likes that bullet. I cast a 8/9bhn hp with that mold. The hp has excellent expansion and weight retention.
https://i.imgur.com/ZxGtzF4.jpg
Kind of funny, people complain about their 9mm bbl's having no throats in them and send them off to doug guy to have them throated. That cheap $200 taurus bbl is throated.
https://i.imgur.com/Q9VqsoF.jpg

I do like the 1911 platform and this is what I mainly use/shoot the 9mm's in.
https://i.imgur.com/a8fXZPh.jpg
Not hand/cherry picked by any means. Nothing more than the test target used that day testing loads. A 10-shot group @ 50ft with those Mihec 125 hp's cast with 8/9 bhn alloy, sized to .358" with a 1100fps load.
https://i.imgur.com/N6XBlbc.jpg
This is what the throat looks like in that factory bbl in that springfield range officer 1911/9mm.
https://i.imgur.com/UyPfNW8.jpg

[charlie b]

I wish my HK barrel looked like that :)

[Omni]

People knock taurus pistols. myself I like the g2c and more importantly, my g2c likes that bullet. I cast a 8/9bhn hp with that mold. The hp has excellent expansion and weight retention.
Kind of funny, people complain about their 9mm bbl's having no throats in them and send them off to doug guy to have them throated. That cheap $200 taurus bbl is throated.

...those Mihec 125 hp's cast with 8/9 bhn alloy, sized to .358" with a 1100fps load.


You won't get any ire from me about Taurus. Unlikely as it sounds, my 9mm is a PT111 G2 just like yours. Besides the key lockout system causing malfunctions until I disabled/removed it; it has been 100% reliable on factory loads. My TX-22 has been just as good if not better.

Since we have the same/similar barrels, I'm curious what the max length you are able to seat the 125gr bullet out to?

Being that I only have a .357" bullet sizer, I'm also curious if you ever tried bullets sized to .357" out of your Taurus?

What velocity do you get out of the shorter G2 barrel?

[hermans]

It's my favorite 9mm bullet. People knock taurus pistols. myself I like the g2c and more importantly, my g2c likes that bullet. I cast a 8/9bhn hp with that mold. The hp has excellent expansion and weight retention.
https://i.imgur.com/ZxGtzF4.jpg
Kind of funny, people complain about their 9mm bbl's having no throats in them and send them off to doug guy to have them throated. That cheap $200 taurus bbl is throated.
https://i.imgur.com/Q9VqsoF.jpg

I do like the 1911 platform and this is what I mainly use/shoot the 9mm's in.
https://i.imgur.com/a8fXZPh.jpg
Not hand/cherry picked by any means. Nothing more than the test target used that day testing loads. A 10-shot group @ 50ft with those Mihec 125 hp's cast with 8/9 bhn alloy, sized to .358" with a 1100fps load.
https://i.imgur.com/N6XBlbc.jpg
This is what the throat looks like in that factory bbl in that springfield range officer 1911/9mm.
https://i.imgur.com/UyPfNW8.jpg

Forrest r
Great post, very nice photos and some excellent shooting!

[dverna]

Beveled bases also take finning out of play. More often than not finning doesn't have any major effect on accuracy. A bullet is swaged down in the bore and fins appear on the bullets base on flat based bullets. The amount of finning (larger diameter ='s more finning) and if a bullet wasn't sized strait or seated/shot straight. The amount of finning will be amplified, and bad things will start to happen.

It's hard to come up with examples of finning but here goes:
A 148gr hbwc cast with 8/9bhn alloy sized to .358" with a +/- 14,000psi 800fps load.
https://i.imgur.com/XVsDo3b.jpg

That bullets base has no finning and shows it was an excellent fit for that revolvers chambers and barrel.

Another hb cast bullet using the same 8/9bhn alloy, a hb hp swc (429422 with a hp added using a forester hp tool). The load was +/- 18,000psi/1000fps and the bullet was sized to .431" to fit the throats of the chambers in a ca bulldog. The barrel of that bulldog is tight .428"/.429". The loaded bullet with the hp and a recovered hp that mushroomed.
https://i.imgur.com/FTFbMo6.jpg

A side view of that same mushroomed hp. It clearly showed 2 things. The 1st was my pc'ing skilled were terrible. I wasn't letting the oven cycle back up to heat between batches and using minimum cure times. Ended up using pid controller and 20-minute cure times (up from 15 minutes) to resolve all of my pc'ing issues. The 2nd thing the picture shows an expanded jagged bullet base (finning) from the bullet being swaged down 3/1000th's+ in the bbl.
https://i.imgur.com/Swqedh0.jpg

+/- 40 years ago I did head-to-head testing casting h&g #50 wc's. 1 mold was a bb the other plain/flat based. Same alloy/sizing die/lube/cases/firearm/etc. Did a bunch of testing (over 800 shots/400 with each bullet) with different loads/powders/357",.358",.359" bullets, fully lubed, 2 lube grooves lubed, 1 lube groove lubed. All testing was done @ 50yds.

2 things came out of that testing:
The bb H&G #50 lubed in the bottom 2 lube grooves sized to .357" was "the" bullet.
No matter what load/lube/size bullet. The plain based bullet always had more fliers.

When I shoot at close range 25yds and closer. A bullets base doesn't matter. Nor does it matter if the targets are large. Take a 25yd load that looks pretty good accuracy wise and step out to the 50yd line and see what happens.

My last failure @ 50yds due to a bullets base. I cast some hb 35870's to test in a 9mm. It's a llloooonnnnggggg bodied bullet. The red bullet is the hb 35870 next to my favorite/standard 9mm bullet (green).
https://i.imgur.com/V87WlTN.jpg

As you see they both have the same oal to be able to chamber. But the hb 35870 sits a lot deep in the 9mm cases going into the web of the 9mm case. This caused too much distortion of the bullets base causing fliers.
https://i.imgur.com/77VoPsa.jpg

Great post sir!