Polygonally rifled .25 barrel loading issue

[Uriel]

I've got a 24" LW polygonally-rifled barrel on my Rapid 7, and am experiencing a strange problem when loading.

I have tried H&N FTTs, Predator Polymags, and JSB King Heavy Mk2 pellets, and all have the same issue.

Essentially, I have to use a fair bit of force to push the pellets into the breech - practically forcing them in. Do I need to size the pellets? Does the breech need a throat? Do you guys have any other suggestions? 

 

[Glem.Chally]

Did you give it a leade a bit?

 

[Lewis]

I'm watching this with interest. I have a similar issue and was considering using a countersink to bevel the entrance a bit.

In my case while loading is a little clunky, accuracy does not seem to be affected. Are you having issues with loading only or is accuracy also affected?

 

[Uriel]

I've spoken to a gunsmith in the interim, and he has suggested that the breech needs a throat.

As to accuracy, I haven't yet zeroed the rifle. It's still a work in progress; it's going to be used for night hunting, with a Photon NV scope. The scope itself needs to be physically moved closer to optical zero, and I'm awaiting delivery of some fully adjustable mounts. Until they've been fitted, the only shooting I'm doing is just to lead the barrel.

I shall, of course, keep you informed. 

 

[Lewis]

Thank you.

Which mounts are you going to use?

 

[Uriel]

These Sportsmatch ones:



https://www.uttings.co.uk/p104304-sportsmatch-uk-2-piece-double-screw-fully-adjustable-high-30mm-mount-atp66/

 

[Uriel]

Before and after going through the polygonal rifling.

 

[Uriel]

Talk about German efficiency! I emailed Lothar-Walther (at about 2am, just before I went to bed), asking for advice, and woke up to find an answer already in my inbox!

 

[Uriel]

I have done as advised by LW, and am testing the rifle tonight. 

 

[Uriel]

The barrel was given a throat in the breech this evening (thanks to my mate, Richard), and now loads as smoothly as you'd want it to. Despite the difficulties of using an NV scope indoors, it was starting to group quite nicely at 25 yards. I need to put some more lead down the barrel. The scope is a Yukon Photon XT with the extreme conversion, and it's got the common problem of running out of adjustment to zero it. I bought a set of Sportsmatch fully adjustable mounts, and practically have it optically centered with them alone. I love a happy ending.