Bullet / Sabot to Bore Fit (Testing) and Load Development Questions

[Usmc22]

Good morning Folks,

I have the following Sabots on order:
- MMP Black
- Black HPH/12
- Black HPH/24
- Black 3Petal-EZ
- Harvester Crush Rib Black
- Note: All are 50cal bore / 45cal bullet

And the following Bullets:
- Hornady XTP 250 grain
- Hornady XTP 300 grain
- Nosler JHP 250 grain

I’m looking to find load combos that I can load / push down with one hand and not bust a blood vessel.

My plan is when the sabots and bullets show up to test each bullet with each sabot and note the ones that fit best.

From there I plan on doing a load work up with Blackhorn 209 powder and CCI209M Primers starting with 70 grains by volume up to 120 grains until accuracy drops off.

As a control measure I will measure my volumetric charge on a scale to ensure its close and note the difference observed.

I’m thinking 2 targets with 5 shot groups each using the following method:
- clean cold bore target #1, fouled bore “follow up“ shot target #2
- swab bore, fire 2 primers to ensure breech plug is clear
- repeat above

Realistically I will not be able to do all bullet / sabot combinations that I initially noted as a good fit on one day.

Am I on the right track for testing?

Any tips or improvements you’d make?

Would you clean the breech plug in between shots?

 

[GM54-120]

300gr XTP in the HPH-24 should not be too tight and not too loose either.

 

[Usmc22]

300gr XTP in the HPH-24 should not be too tight and not too loose either.

Will test all of them and probably post a picture of the recorded results. Its just me as a sample size so it could be taken with a grain of salt but may be useful in guesstimate‘s.

 

[rangerod]

Looks like a good plan. I have a T/C Triumph with a very tight bore that takes the 3 petal. The xtp's are a good choice also.

 

[Rainorshine]

I want a combination that offers maximum effectiveness out to 200 yds and the flattest trajectory so holdover is minimized. I think I would focus on finding a combination using 100grV or more BH 209 so I would start at 110grV

Also I like to fire 3-shot groups with the first shot through a clean bore and then two more shots through the fouled bore. Sometimes there’s not enough difference to matter so that’s good to know. Since I’m mostly interested in deer hunting loads bug-hole precision, while nice isn’t necessary.

So I guess what I’m trying to say is that if it’s a deer hunting load consider starting and designing your tests at the load you deem most appropriate for your max yardage.