250 gr. FTX load question

[Weapon of Choice]

Took my new rifle out for the first shots yesterday. I loaded up some 250 gr FTX using the Hornady data and components. The load was 37 grains Lil'Gun, new Hornady brass, WSR primer.OAL was 2.23. Loaded with new Hornady dies and taper crimped. According to the data I should have had a mv over 2100 fps but I was only getting around 2050. Any ideas why? Would it be due to a new barrel?

[Siringo]

This is difficult to tell. In my carbine -- I get 2200+ fps. All barrels will exhibit differences in velocity. Shoot some factory ammo and see what you get for results. Also, it could be your chronograph. I make sure mine is in the shade and not direct sunlight. If the shadows are skewed, it got some weird reading.

[Hoot]

The neck tension is real important to get maximum velocity. I set my taper crimp to .476 resultant mouth diameter and got higher velocities and better SDs to boot, without any signs of excess pressure. Initially, I was using .478 and with the 250s, chambering made them creep forward more than I cared for, so I went tighter. No problem with .476 catching plenty of lip. As a matter of fact, I go to .475 with the lighter FTXs. Also, go easy if not entirely skip the expander step. Better tension from that also.

Hoot

[Weapon of Choice]

The neck tension is real important to get maximum velocity. I set my taper crimp to .476 resultant mouth diameter and got higher velocities and better SDs to boot, without any signs of excess pressure. Initially, I was using .478 and with the 250s, chambering made them creep forward more than I cared for, so I went tighter. No problem with .476 catching plenty of lip. As a matter of fact, I go to .475 with the lighter FTXs. Also, go easy if not entirely skip the expander step. Better tension from that also.

Hoot

I had trouble seating without expanding enough to get the base of the bullet into the case but maybe I did not chamfer enough. Initially, I chamfered and expanded a little but had to go back and chamfer more and expand more. I have no idea what diameter I crimped to. I set a case in the holder and raised the ram all the way, screwed in the taper crimp die until contact with the case. Removed that case and put one in with a seated bullet and adjusted the crimp down 1/4 turns until I had what looked and felt like a firm crimp. Seemed about maybe just a little less arm pressure than I would use roll crimping a medium 44 mag load.

Are you getting that diameter measurement from the outside of the case with a bullet seated? This taper crimp is all new to me.

[Siringo]

WoC -- I do not chamfer my cases or expand them. If I trimmed, which is rarely - if at all, I might just break the sharp edge, but you need some sort of a 90 degree edge on the case to "bite" into the bullet jacket and to headspace on. If you chamfer to much, there will be no edge. I will taper crimp to .476". I do not expand because I want as much neck tension as possible with the die set and definitely I do not bell. IF your seating die is adjusted correctly (set to a depth just before the case would contact the internal crimp) the bullet should enter straight -- especially with the 250 gr FXT with the generous radius at the rear. The Hornady seating dies utilize a floating straight seating system that has worked well for me.

I do not use the side crimp and rely on case neck tension instead. In preparing my cases, the necks are thoroughly cleaned -- no lube, no powder residue, no carbon before I would seat the bullet. I try to get them as close to factory new. When sizing using the Hornady die set, the internal neck diameter will be around .446". Using the expanding die, this brings the internal diameter up to .448". By not expanding, I increase my neck tension by .002".

Regarding your chrono -- shoot a 22 lr over it and see what velocity you get. Wildcatter does this for calibration - I think!

Please keep in mind that this is what works for me and others have different approaches, but my goal is to create a reload that is as close to factory fresh as possible -- with the exception of some weird project that has no bearing on anything other than I can just do it.

[Weapon of Choice]

Siringo, Thanks for the reply! I will try this next batch with no expander die. Without the chamfer, the cases were cutting into the bullet jacket and I was putting so much pressure on the bullet to seat it, the die was also cutting a ring around the tip of the bullet. Also, I did run the new brass through the sizer die first.

[Siringo]

I should clarify that my loading procedures are with fired cases. I did get a batch of brand new brass and did as you have -- size and expand. Just to make them uniform. I never know on new cases whether they are the correct dimension or not.