Optima V2 accuracy challenge

[Sideshow]

Just as a FYI --- Use a machinest tool called a small hole gage , tbey are inexpensive and adjustable , to measure your bore . Then mic the gage , this is your bore size . Now take a sabot w bullet in it and measure it along the bearing surface (the sides of sabot & bullet assembly) . For best fit and function the bullet sabot combo should be .002 to.003 larger than your bore . THIS is what matters MOST . Anything else is just details of bc , bullet preformance on impact , etc . Oh yea the bullet MUST seat all the way in the sabot no strain no fuss no.pushing the sabot petals open--- nothing . I dont care what the names on the shiney package are . THIS is how its done . It will load with 25 to 35lb of pressure when its right in ANY rifle . Heavy loads may require a base sub and/or a tougher sabot . Same fitment along with roughened up bullet sides so bullet wont spin inside sabot . This is what works .

 

[GM54-120]

I have a few loads that like a very tight sabot but for the majority a .003-.004 sabot size over lands is in the ball park. Dirty powders a tiny bit less but with BH209 that has been solid for me every time. Barnes for example i always have better luck tight. Parker BE and softer cup and core bullets seem fine with easier loading sabots.

So if your bore is .501 on the lands you want to start with sabots in the .503-.504 range with your bullet. Just remember not all 45cal bullets are .451. Many are .452 or even slightly over. Barnes can be slightly less. A longer sabot but the same loaded OD will also feel tighter if the bullet is long enough.

 

[Sideshow]

I have a few loads that like a very tight sabot but for the majority a .003-.004 sabot size over lands is in the ball park. Dirty powders a tiny bit less but with BH209 that has been solid for me every time. Barnes for example i always have better luck tight. Parker BE and softer cup and core bullets seem fine with easier loading sabots.

So if your bore is .501 on the lands you want to start with sabots in the .503-.504 range with your bullet. Just remember not all 45cal bullets are .451. Many are .452 or even slightly over. Barnes can be slightly less.

Not too bad GM54--120 !!! I figured they needed a method to achieve success . Gotta start somewhere not just throw your wallet at them . This is why a bulk bullet and sabot buy is better . Bring along your calipers !!!

 

[GM54-120]

My old stock Parker BEs are .4505. You put that in a sabot that is ok with a .452 XTP and there is a good chance its gunna be horrible. The simple solution is a Lee .451 sizing die. Run all your bullets through it. The die is $20-$25. Then you got a good chance of all your bullets working in the same sabot.

 

[Sideshow]

My old stock Parker BEs are .4505. You put that in a sabot that is ok with a .452 XTP and there is a good chance its gunna be horrible. The simple solution is a Lee .451 sizing die. Run all your bullets through it. The die is $20-$25. Then you got a good chance of all your bullets working in the same sabot.

Brilliant !!!

 

[GM54-120]

It works but if you got a really large bore...not so much. Works well in bores that are in the .500-.501 range ON THE LANDS. If your bore is .502 on the lands then only the HPH-12 puts you in the "should work zone". I got a .454 die also for .458s. Works really well with a Harvester black crushrib in a semi loose bore. If you got a really really sloppy bore you can use a .458 or .457 bullet in the black crushrib.

 

[Sideshow]

It works but if you got a really large bore...not so much. Works well in bores that are in the .500-.501 range ON THE LANDS. If your bore is .502 on the lands then only the HPH-12 puts you in the "should work zone". I got a .454 die also for .458s. Works really well with a Harvester black crushrib in a semi loose bore. If you got a really really sloppy bore you can use a .458 or .457 bullet in the black crushrib.

Listen guys --- these are gold nuggets being tossed out there !!!! Thank you !!!

 

[Sideshow]

Listen guys --- these are gold nuggets being tossed out there !!!! Thank you !!!

Any more brillance for the 54 cal boys GM 54--120 ??? These can be difficult to size up a combo for !!! Not much to choose from on this one !!! Especially if your kinda big on the bore !!! I actually have a barrel like this . I miss my bazooka !!! These 54's get ignored alot and that is a shame !!!

 

[Sideshow]

It works but if you got a really large bore...not so much. Works well in bores that are in the .500-.501 range ON THE LANDS. If your bore is .502 on the lands then only the HPH-12 puts you in the "should work zone". I got a .454 die also for .458s. Works really well with a Harvester black crushrib in a semi loose bore. If you got a really really sloppy bore you can use a .458 or .457 bullet in the black crushrib.

I goofed , this shouldve been on my previous reply...sorry

 

[GM54-120]

I shoot almost entirely MMP 54x50 sabots and by far the best bullet to shoot is the Speer 50cal 325gr bullet. I got a ton of those sabots. The other is the Rainier 50cal 335gr HP and those are super duper cheap to shoot.

Speer 50cal 325gr https://www.midwayusa.com/product/1010539076?pid=374753

In a really large 54cal get the Harvester 54x45 and shoot a 458 bullet. That is one crazy tough sabot but pretty loose in mine unless you use a .458 in it. Then its very tight.

 

[Sideshow]

I shoot almost entirely MMP 54x50 sabots and by far the best bullet to shoot is the Speer 50cal 325gr bullet. I got a ton of those sabots. The other is the Rainier 50cal 335gr HP and those are super duper cheap to shoot.

In a really large 54cal get the Harvester 54x45 and a shoot 458 bullet. That is one crazy tough sabot but pretty loose in mine unless you use a .458 in it. Then its very tight.

You may have just achieved hero status for MANY , i include myself in that too !!!! I LOVED my 54 !!! Your experiance is indeed vast !!!!!!

 

[GM54-120]

No, Tony Knight got it right the first time. The Speer 325gr in a 54x50 sabot was the bullet that shipped with the MK85 54cals. Barnes 275gr is also good but way more exensive to shoot. That Speer will slam anything with hooves.

I stumbled upon the Harvester 54x45 only because i had some Barnes 300gr 458SOCOM bullets that didnt shoot worth a hoot in my 50cal. I tried one and pure dumb luck gave me one of the best shooting loads i ever shot in a 54cal. A max load of BH209 dont begin to phase that sabot. I almost bought a Rem700ML 54cal just to shoot that combo a little faster.

 

[ShawnT]

I shoot almost entirely MMP 54x50 sabots and by far the best bullet to shoot is the Speer 50cal 325gr bullet. I got a ton of those sabots. The other is the Rainier 50cal 335gr HP and those are super duper cheap to shoot.

Speer 50cal 325gr https://www.midwayusa.com/product/1010539076?pid=374753

GM recommended these to me several years ago. The both shoot fantastic from both my MK-85 and MK-95 .54's. Both are hard to beat on price and accuracy.
I also make my own .500 lead bullet for sabots too.

 

[Sideshow]

No, Tony Knight got it right the first time. The Speer 325gr in a 54x50 sabot was the bullet that shipped with the MK85 54cals. Barnes 275gr is also good but way more exensive to shoot. That Speer will slam anything with hooves.

I stumbled upon the Harvester 54x45 only because i had some Barnes 300gr 458SOCOM bullets that didnt shoot worth a hoot in my 50cal. I tried one and pure dumb luck gave me one of the best shooting loads i ever shot in a 54cal. A max load of BH209 dont begin to phase that sabot. I almost bought a Rem700ML 54cal just to shoot that combo a little faster.

Yea i had no choice but to quit trying to find a sabot tbat would work . I cant even put engraveing on a 54,.500 mmp anymore to be totally honest . It used to sboot tbat combo excellant . Loaned it out ( bk--92 )and got back a mess . Rust . Got it clean and smooth but no more sabots . HAD to use conical tbat is Big , .550 big , and tbats a slip fit !!! Shoots really well but got tired of the hassle and put on a take off Rem UML barrel . Its awesome BUT i miss THE BAZOOKA !!! Who knows maybe i'll find anotber 54 barrel one day and make a switch barrel combo . 60ft lbs is really all it would take . Thought of having the 54 redone to a 58 and tben the Rem barrel popped up for peanuts . Momma pinched the heads off the dumb ones ....LOL !!!!

 

[Sideshow]

No, Tony Knight got it right the first time. The Speer 325gr in a 54x50 sabot was the bullet that shipped with the MK85 54cals. Barnes 275gr is also good but way more exensive to shoot. That Speer will slam anything with hooves.

I stumbled upon the Harvester 54x45 only because i had some Barnes 300gr 458SOCOM bullets that didnt shoot worth a hoot in my 50cal. I tried one and pure dumb luck gave me one of the best shooting loads i ever shot in a 54cal. A max load of BH209 dont begin to phase that sabot. I almost bought a Rem700ML 54cal just to shoot that combo a little faster.

GM54--120 what youve shared here today is of GREAT VALUE and the technical knowledge . I confess , again , that i did spoof a bit on my 54 . However it was fueled by a GREAT love of that bore and a deep saddness for its disapperance in a modern version . I KNEW you had the answers for those that need that info . ALL youve shared here today truly NEEDS to be put in a special spot on MM instead of just buried here in a bit of obscurity . You have done a wonderfull thing . Just wanted to express that right here , right now to you Sir . That knight info fits in that as well for thanks and its helpfullness . Twas a rare gift beyond your busy , helpfull activities .
Well done , very well done....
Bob , better known as "Sideshow"

 

[Far Sighted]

Earlier non-QRBP plugs needed a little work to be a really good plug. Ron modded some and they were great after being modified. Unmodified they are mediocre at best. If the head space is tight (seals the primer well) and you keep the 3mm flash channel clean they work to some extent. Increase the flash channel to 5/32 with a vent liner installed and they go bang every single time. Been there and done that in a 2009 model Accura 45.

Thanks GM,
Yes on the head space subject I was checking that feature on three Optima ML mentioned above. I found by using aluminum fold as a feeder gauge and doubling it several time I could get a number. It was 0.005" on my V2 and my son's V1 but my Pro had excessive to 0.010" . I don't know what the target is at the factory but least possible is probably better. I made adjustments to get headspace down to almost nothing. In the last test of the V2 it was consistent and had almost no blow by. Blowby was getting by where the slots are on the firing pin housing face as expected.

The adjustments were done by turning the breech plug CCW until the action just locks. Also the firing pin housing screw was raised turned CCW to close the headspace. Shims would be better but I thought this would be ok short term. I will try on the other two as a test. I also used used just under to wraps of Teflon thread seal on the V2 breech plus only on the front end. It is a waste to apply it on any all threads because the blow by doesn't past the wrapped portion at the front.

I will entertain the option of mods and do have #65 drills if I want to increase the flash hole size. Some have indicated having success making the flash channel larger as you indicated.