Dakota 375HH ammo issues

[ChooChoo404]

FWIW, (no riflesmith here) I have a 76 in 375hh and it eats all sorts of factory ammo like a toddler scarfs pasta.

Once in a very great while with beat to hell snap caps the very last ie 5th to cycle will balk.

Check for anything impending the mag follower? Freckling on the ramp?

There is no Dakota any more. ParkWest, and theyve been nothing short of outstanding in every way. Massive thimbs up.

 

[Riflecrank]

In 2001 I had same problem with Swift A-Frame bullets not chambering in a .416 Rigby.
The bullet was full diameter too far forward of the cannelure before starting into the ogive curve.
Later production by Swift had changed to a longer ogive and those 400-gr/.416-cal A-Frames chambered just fine.

Both the .375 H&H and .416 Rigby have no parallel-sided free-bore,
have leade-only throats.
The base of the leade in the .375 H&H is 0.390" wide, and has a rather abrupt leade hemi-angle of 2 degrees.
So, this throat tapers down to bore diameter of .366" over a run of only 0.361" out of case mouth, when brass is 2.860" long.
A full diameter bullet will be bumping the 0.375" diameter where the throat starts turning into lands and grooves of the rifling much closer than that.

It is a nose projection and ogive length thing most likely.
Don't change the rifle, change the bullet.
Maybe the newer make of Swift bullets will work just fine ?

 

[ChooChoo404]

Find myself wondering if one could burr the mouth of the chamber with careless, sloppy, and enthusiastic application of a steel cleaning rod.

 

[ChooChoo404]

“Don't change the rifle, change the bullet.”
Factory!

 

[deewayne2003]

In 2001 I had same problem with Swift A-Frame bullets not chambering in a .416 Rigby.
The bullet was full diameter too far forward of the cannelure before starting into the ogive curve.
Later production by Swift had changed to a longer ogive and those 400-gr/.416-cal A-Frames chambered just fine.

Both the .375 H&H and .416 Rigby have no parallel-sided free-bore,
have leade-only throats.
The base of the leade in the .375 H&H is 0.390" wide, and has a rather abrupt leade hemi-angle of 2 degrees.
So, this throat tapers down to bore diameter of .366" over a run of only 0.361" out of case mouth, when brass is 2.860" long.
A full diameter bullet will be bumping the 0.375" diameter where the throat starts turning into lands and grooves of the rifling much closer than that.

It is a nose projection and ogive length thing most likely.
Don't change the rifle, change the bullet.
Maybe the newer make of Swift bullets will work just fine ?

Thank you for that detailed and I believe correct description of what’s going on.

Personally, I don’t like having a dangerous game rifle that won’t run certain ammo.

 

[Tucketed]

@Schüler Jumbo and @Riflecrank thank you much for your insight and knowledge. I really appreciate the ideas.

 

[Tucketed]

Thank you @Schüler Jumbo I ordered the Hornady OAL tools this morning.

 

[Joker12]

The rifle is short throated. A hunting rifle should chamber any normal hunting bullet, reliability in the one essential. Have a gunsmith ream the throat deeper.

 

[Tucketed]

@Joker12 yep that should work after August hunt. Took it for a drive today with TSX and she shot great a true MOA. Just need to swap the scope to my Swarovski 1-6 even though the Zeiss Victory on it is nice. I know the lead sled is a no no to many but no weight and an extra decelerator pad has always worked for me.

 

[PARA45]

You can’t go wrong with the TSX bullets & ammo. My CZ rifle likes them and no issues killing a cow and bull Cape Buffalo with the TSX factory ammo.