I have a relatively new (I bought it brand new at Walmart), prolly 14-6mo old, Rem 700 .243 basic SPS that I bought from Walmart. Before shooting it a single time, I replaced the trigger with a Timney trigger. I am no certified gunsmith, but installing one is NOT rocket science and this isn't my first go at them either. But, I have light strike issues with multiple different good quality ammo (Hornady, Nosler, etc)...the primer is struck, but not as hard as primers on a round that actually does fire. I have even reloaded the same round and after two or three times, it will finally fire. other times there is no issue and four or five rounds will fire fine.
Two questions:
what do you think might be the cause?
what course of action would you take to fix, i.e. some self smithing, send back to Remington, take to local gunsmith, etc?

I don't think Remington will take it back now that you've messed with the trigger.

i still have the original trigger that can easily and quickly go back in.

Put the stock trigger back in and see if that fixes it.

Do you know anyone with a headspace gauge? Also did you pull it apart and clean inside the bolt etc? Is firing pin assembly screwed completely on? Seems trivial but you never know.

Put factory trigger back in like said above. If still not firing, dissamble bolt. Sometimes too much grease or even a broken firing pin will do this.

Loosen the overtravel on the trigger you got and see if that helps. It may be letting the sear drop enough to let the FP go but still drag on it.

Remington use to coat the trigger screws so they could tell when it had been messed with.

I read on another forum that some Remington 700s require a longer sear, and if you have light primer strikes with a Timney, jut call Timney and they can send you the part to make it work.

Normal 700 trigger is 510
One with the longer sear is 510-U ( Universal)

"SPS Varmit is one model that Timney is aware has the problem, mine does. Timney just made a production change to a longer sear so it appears they have recognized the issue and have made a universal fix. They asked me to ship my trigger back and they'll replace it, no offer of direct shipping the correct sear."

Thanks Colt W. Knight! I will try that.

And thanks all others too for the input.

I believe they can easily tell if it has been removed, think they paint some type of proprietary paint/locktite on the triggers to tell if they have been tampered with.

Having said that I would put the stock trigger back on the rifle and then shoot some factory ammo through it(by factory I mean Remington brand)

If you are still having the issues; I would send it back.....

FYI I think Remington along with other manufactures have a separate grade of gun that is Wal-Mart grade = Meaning they are made as cheap as possible to be sold at Wal-Mart.