How short is too short 124g MBC small ball?

[z7]

On the mbc website it says load to 1.08" but with my lone wolf barrel they won't pass a plunk test until 1.04".

Alliant data for a 124 lead and be-86 oal of 1.12"

This is for 9mm luger. I really don't want to be dangerous and I also want ammo that will function and be relatively accurate

Thanks

 

[Comrade Mike]

4 thousandths is nothing. Work up as you usually do using cast data and I doubt you'll run into any problems.

 

[1KPerDay]

Start low, work up, stay around midrange or lower, IMO. Are you using BE-86?

 

[Gadawg88]

Just for the record, the difference between 1.04 and 1.08 or 1.08 and 1.12 is 4 hundredths, not thousandths. Follow the standard advice, start low and work up and you should be fine.

 

[Rule3]

I have to load them real short in my CZ so as mentioned just use the start load of whatever powder. It is a odd shape bullet has a fat head

 

[z7]

Thanks for the responses, I will be using BE-86. Alliant data is a max of 5.7g at 1.12", I plan to start around 4.8g and work up using .2g increments. To 5.6g looking for accuracy and function. My planned oal will be 1.04" crimping only to remove the bell on the case mouth. I will post a range report when I get around to it.

 

[Sunray]

1.08 minus 1.04 is 40 thou, not 4.
OAL for a 124 grain jacketed bullet is 1.169". 1.150" for a plated RN.
1.12" is the minimum length. Use the max OAL. Or just below the lube ring.

 

[ssyoumans]

I've shot tons of these. They have a very different shape to them than traditional 124gr bullets. They are much shorter than other lead 124gr bullets and even though they have to be loaded very short OAL to pass the kerplunk test with your barrel, if you compare to other 124gr bullets, you will see they both net the same amount in the case, which is what matters. They work well in my P225 and Glock 23 with Lone Wolf conversion barrel.

 

[Comrade Mike]

Just for the record, the difference between 1.04 and 1.08 or 1.08 and 1.12 is 4 hundredths, not thousandths. Follow the standard advice, start low and work up and you should be fine.

What he said.

Forgive me I was still in wake up mode when I read that thread. My mistake is a good reason why you should always take Internet advice with a bit of common sense.

 

[1KPerDay]

1.08 minus 1.04 is 40 thou, not 4.
OAL for a 124 grain jacketed bullet is 1.169". 1.150" for a plated RN.
1.12" is the minimum length. Use the max OAL. Or just below the lube ring.

Or you could listen to people who actually use this particular bullet. Load them to "max OAL" or even 1.12 and they will jam into the rifling.

 

[moxie]

I load scads of them at 1.116". Work great in my M&P9c.

 

[ARJJ]

Like others said, they have a "fatter" profile than other round nose bullets. I have a Lone Wolf stainless barrel for my G19, and I have to load Smallballs at 1.05" to get them to plunk. They feed and shoot fine, just look odd loaded.

Because of this shorter OAL than what was published in my manuals, I used a starting charge that was a couple tenths of a grain under the published starting loads. No problems doing so.

 

[Sam1911]

I tended to load those at 1.09" so they'd pass the "plunk" test in my xDM9 and some other guns with short leade.

 

[TimSr]

OAL is a totally useless measurement unless you are using the EXACT same make and model bullet as the spec is written for. If you particular bullet is .05" shorter than the one published, your OAL should be .05" shorter.

The critical measurement is seating depth which should always be the same for a given bullet weight. OAL is used as an external measurement to figure out how deep it is seated. Its like figuring out how deep a stick is in the mud by measuring the part you see sticking out. It only works if you know long the stick is.

If I were king I'd throw out all OAL specs and ban them, and replace them with a simple basic math formula for simply measuing your bullet length to give you the correct OAL for the finished cartridge. That or someting visual on the bullet to reference like the cannelure of a revolver bullet.

 

[z7]

I guess this is where the art portion of the reloading science is, so many bullet/brass/powder combinations that to figure our what works becomes an art, based on science. There are limits to what you can/should do, safe deviations and then there are things that will blow up in your hand. I am cautious when my limbs and digits and eyesight are concerned

 

[z7]

I went and tried them out today, 10 rds each at 4.6g to 5.6g of BE-86 in .2g increments. oal 1.045"
At 10 yds I shot 5 RDS from each of my LW conversion barrels and guns (glock 23 and 27)

I am going to repeat with 50 or 100 rds at 5.0 to assess and check for leading. It all shot very well, but the groups seemed to open and the recoil was snappy starting at 5.2g. I believe at 5.6 I was at or slightly above what I would consider max charge for this load, YMMV
thanks for the help

 

[rsrocket1]

QuickLoad Estimate

Disclaimer: This is simply an estimate with Quickload and not real data. YMMV

Take a look at the Lee 356-124-2R bullet, I think the MBC's are close to that profile.
While this is just another WAG, Quickload says 5.6g Power Pistol (not BE-86, but allegedly close) gives a Max Pressure of 35,000 with the 356-124-2R seated to a 1.080" COL (.264" Seating Depth which TimSR correctly points out is the important parameter).

A 1.045" COL or .299" SD gives a Max Pressure of 47,500 psi. This might not blow up your gun, but it shows how much the pressure changes with 40 thou of seating depth change with a small cartridge.

 

[z7]

Thanks for the QL info, I suspected with my short oal I would find a middle of the road/lower end charge that worked well and was safe
Alliant lists 5.7g as max, but I will not be exceeding 5.2 with this combo based on how it shot today

 

[LiveLife]

How short is too short 124g MBC small ball?
On the mbc website it says load to 1.08" but with my lone wolf barrel they won't pass a plunk test until 1.04".

Alliant data for a 124 lead and be-86 oal of 1.12"

If you look at the comparison picture below of MBC SmallBall loaded to 1.080", due to shorter but more rounded nose shape (see comparison picture of SmallBall to "stepped" Dardas/ZCast RN at bottom), the bullet base/bearing surface of the bullet will hit the start of rifling sooner than FMJ/CN bullets with longer nose.

My Lone Wolf 40-9 conversion barrels for G22/G23/G27 with gradual start of rifling angle and like KKM barrel with longer leade/freebore, will accommodate MBC SmallBall loaded to 1.080"-1.100". But my latest Lone Wolf 40-9 barrel for G23 (change in Wolf logo on barrel) has shorter leade and sharper start of rifling (Like my Sig 1911 barrel) and I need to seat the bullet deeper.

Seating Small Ball with substantial bullet base deeper will definitely increase chamber pressure (not to mention compressing the powder charge which will spike chamber pressure). I would determine bullet seating depth by subtracting the bullet length from OAL then see what the max case fill is for the powder you are using (fill powder to bullet seating depth and weigh).

So with this barrel, when using powders/charges that will be compressed, I instead use "stepped" RN seated to longer 1.125" OAL as the stepping of the bullet base prevents bearing surface from hitting the start of rifling with shorter leade barrels (see bottom picture of Dardas/ZCast stepped RN).

 

[Blue68f100]

This is why your suppose to work up your loads. Jumping to max load can be very dangerous. Some powders are more sensitive to case volume than others. A little as 0.040"-0.050" can double the pressure in some powders/bullet combos.

Always workup your loads once the OAL has been determined for your gun.

 

[rsrocket1]

OT bds, but look at the differing lengths of those cases!
Just goes to show you that 9mm varies all over the place. Guns, cases, bullets.

 

[LiveLife]

OT bds, but look at the differing lengths of those cases!

Yes, definitely off topic and all my fault. When I took the picture of rounds, I somehow cascaded them at an angle and did not catch the "flaw" until I posted the picture on THR server. I was too tired (more likely lazy ) on that night and did not want to go back into the reloading room to take another picture with the cases lined up straight facing the camera.

So the case lengths are not different or optical illusion, just poor picture staging on my part <--- still human and FULL of mistakes.

The lead bullets in comparison are lined up straight and properly facing the camera.